# Curtis sno-pro 3000 wiring questions



## 2old2shovel (Nov 15, 2020)

Hi all,

Bought an unknown year Curtis Sno-Pro 3000 on a rotted out chev truck that was not road worthy at all. No lights or anything on it just the plow which worked great, so I decided to mount it to my truck and plow the drive at home with it too. Trouble is now that Im about to wire it all up with legit lights and everything I seem to be lost with what diagrams I can find online.

Long and short of it is the truck side harness has all the headlight plugs and relay bank to switch the plow lights on and truck lights off but there is no wiring leads to go into the cab for a toggle switch as the diagram on page 27 in the PDF attached here shows. The only control I have in the cab with the Curtis harness is a 9 pin plug that connects to the joy stick for plow control. Anyone have any idea how the lights switch on and off with this set up? The harness all looks to be Curtis OEM correct minus the leads for the light toggle switch meaning it does not look to have any leads cut out of it. THis harness looks like it came this way. The only thing I noticed thats different is the 9 pin plug for the joystick has all 9 pins in use where the diagram below shows only 7 are used. Maybe this info helps?

http://snoproplows.com/wp-content/u...Steel-Installation-Manual_pdf-303-27675-1.pdf


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## dieselss (Jan 3, 2008)

Post pics of what you have


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## 2old2shovel (Nov 15, 2020)

Heres the main connector


This is the plug for the joystick inside cab


This is the truck side light harness and all other wire connections. There is no other leads in or out of the harness than these pics. It all looks factory made to me is that the case or?


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## dieselss (Jan 3, 2008)




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## 2old2shovel (Nov 15, 2020)

Yes I have that diagram and do not have that plug so how do the lights work? Is it as simple as flipping the switch on the joystick on to power on the lights or?


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## dieselss (Jan 3, 2008)

I do not know. Might just be as you plug the main plow plug in, and turn on your truck light they automatically switch over to plow lights


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## 2old2shovel (Nov 15, 2020)

Certainly worth a shot thanks for the replies. I was concerned mostly that I dont cook any wires, theres a lot of spaghetti in there.


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## Randall Ave (Oct 29, 2014)

Go to page 54, wiring diagrams there.


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## 2old2shovel (Nov 15, 2020)

Thats a far better manual than what I was able to find, thank you very much


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## 2old2shovel (Nov 15, 2020)

Hmm well I connected the headlight harness to the truck and now both high and low beam headlights turn on all the time. Any thoughts on this? I have no plow attached yet, and the joystick is not connected either, only the headlight harness to the truck with the relay pack. 2000 GMC sierra


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## cwren2472 (Aug 15, 2014)

I'm not very familiar with Curtis, but on other makes that happens when the headlamp connectors are crossed. That should have reversible connectors labeled A & B. All connectors will need to be on the same side (and which side that is, you'll have to trial and error)


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## 2old2shovel (Nov 15, 2020)

You mean crossed left/right or crossed high beam/low beam? I dont think it would be possible to cross left/right ( dr/pass ) due to the length of harness and battery location. Unless this harness was for a different vehicle? Dang


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## cwren2472 (Aug 15, 2014)

neither, crossed Positive and Ground
Flipping the connector reverses the + and -


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## 2old2shovel (Nov 15, 2020)

I'lll try that thanks


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## 2old2shovel (Nov 15, 2020)

That worked thanks again. There was some odd LED headlights in there and when I flipped the plug around they wouldnt work at all so I tried some standard halogen bulbs and now things seem normal. Thats the trouble with old stuff, who knows who did what work to it? We have to pay the price up front for brand new or out back with work and frustrations for low cost eh? This has been a chore I hope the rest of the install isn't as confusing.


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## 2old2shovel (Nov 15, 2020)

Argh. Well it worked once, now they are all stuck on again so I pulled the plow harness off entirely and connected back as per OEM headlights only no harness and the high and low beams are stuck on. I can turn them off with the switch or outdoors with the sunlight switch but both come on together and I am feeling pretty whipped by this thing. Any thoughts?


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## cwren2472 (Aug 15, 2014)

You lost me above with the LED and halogen. What does the truck have in it right now, LED aftermarket assemblies or the original halogen?


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## 2old2shovel (Nov 15, 2020)

halogen


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## cwren2472 (Aug 15, 2014)

Does the high beam indicator read correctly on the dash or is it stuck on?


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## 2old2shovel (Nov 15, 2020)

stuck on


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## cwren2472 (Aug 15, 2014)

Disconnect the high beam connector from the lamp, DS first, then PS. See if disconnecting either or both causes it to shut off.


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## 2old2shovel (Nov 15, 2020)

That worked! Why? What I have right now is completely OEM headlight connections and bulbs working as it should. Should I try again with the plow harness?


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## cwren2472 (Aug 15, 2014)

To be honest, I have no idea why that worked. The problem is the same as before - the positive and ground from the high beams and low beams are crossed. If you are 100% sure that you fully disconnected the plow harness from both sides, there shouldn't be any way for those two headlights to interfere with each other without the plow harness on there. Perhaps you have a bad high beam switch? That's pure speculation though. 

Yes, you should be able to hook the plow harness back up now and have it work, albeit with no high beams obviously.

I would just triple check that you did not miss one of the 4 plow connector pairs.


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## 2old2shovel (Nov 15, 2020)

I unplugged the DS high beam like you suggested, turned the lights on and both low beams came on, and the high beam indicator was off. I toggled the high beam on/off a few times and the pass high beam worked fine as did the indicator so I hooked the DS high beam back up and now all four lights and indicator are working as normal. 

I am going to plug the plow harness back in and see if there are any gremlins, if there are I am going to run a separate wiring circuit for the plow lights and just leave the stock headlights functioning. I already had a thought to make a tiny LED lit dome cave type thing to place over the sunlight sensor to turn them off when I need plow lights. Hopefully the turn signals dont cause issues. I will report back what happens thank you again you guys have been very helpful


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## cwren2472 (Aug 15, 2014)

2old2shovel said:


> I unplugged the DS high beam like you suggested, turned the lights on and both low beams came on, and the high beam indicator was off. I toggled the high beam on/off a few times and the pass high beam worked fine as did the indicator so I hooked the DS high beam back up and now all four lights and indicator are working as normal.


No idea why that would fix it. Don't be surprised if the problem resurfaces.



2old2shovel said:


> I am going to plug the plow harness back in and see if there are any gremlins, if there are I am going to run a separate wiring circuit for the plow lights and just leave the stock headlights functioning. I already had a thought to make a tiny LED lit dome cave type thing to place over the sunlight sensor to turn them off when I need plow lights. Hopefully the turn signals dont cause issues. I will report back what happens thank you again you guys have been very helpful


That may be an easier solution

You might be able to just pull a fuse for the DRL to disable them if need be


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## Randall Ave (Oct 29, 2014)

Can I make a suggestion, put the truck back to factory and wire up the headlamps on the plow with a toggle switch. You can run the wires into the plow harness plug on the truck side. With the wiring diagram it will be easy.


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## Randall Ave (Oct 29, 2014)

cwren2472 said:


> No idea why that would fix it. Don't be surprised if the problem resurfaces.
> 
> That may be an easier solution
> 
> You might be able to just pull a fuse for the DRL to disable them if need be


I know why, its a Curtis. I've done over 100 installs on these, very sad face.


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## 2old2shovel (Nov 15, 2020)

The plow and controller has worked flawlessly its only become an issue when I tried to hook up the lights. Randall I think your advice is what I will do. Im going to plug the plow harness back in one more time and see if it does the high beam thing again and if it does i'll abandon the Curtis wiring harness for lights and run a toggle with a relay and some sort of switch to turn off the truck lights. Awful dumb of GM to not be able to turn the dang headlights off on these trucks.


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## 2old2shovel (Nov 15, 2020)

Harness and or relay bank is shot on the Curtis harness. I only plugged in one side to test and same high beam issue. Disconnected and all is fine with the truck so not going to use the Curtis headlight wiring at all.

This plow had no lights on it when I bought the truck it was a yard truck only so I bought a buyers products snow plow light kit on ebay but it has no relays only a toggle. I like the idea of using the Curtis harness to splice into so I can use the quick connect feature which I will do bypassing all the headlight double connectors and Curtis relays of course.

What is the best way to wire up these buyers products lights? I would assume using a NEW relay or two?


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## cwren2472 (Aug 15, 2014)

2old2shovel said:


> What is the best way to wire up these buyers products lights? I would assume using a NEW relay or two?


You could but it's really not necessary. We just use a 3 position position switch and power them directly through it. The lights don't draw enough to require a relay. The plow makes use relays because they have to switch the OEM lights off in the process.


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## 2old2shovel (Nov 15, 2020)

Ok thanks. Any tips on where to route through the firewall? Do I drill a hole or is there a factory spot I can squeeze these into?


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## cwren2472 (Aug 15, 2014)

Beats me - I'm a counter jockey that doesn't actually install stuff. Can't help you there.


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## dieselss (Jan 3, 2008)

I would still use a relay, that way you could run smaller wire up to the switch into the cab....say 20 or 16g and then the relay to the lights say 12 or 14g with an inline fuse in there


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## 2old2shovel (Nov 15, 2020)

Ya Im a fan of relays whenever possible, i had some old turds with hot wires on switches ( jeeps and whatnot ) that caused me some less fun moments back in the old days. I have a box of assorted relay stuff I got at auction here Im sure I could sort that out. Still trying to find th ebest way through the firewall save for drilling and installed a gromet


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## Randall Ave (Oct 29, 2014)

2old2shovel said:


> Ok thanks. Any tips on where to route through the firewall? Do I drill a hole or is there a factory spot I can squeeze these into?


Your not thru the firewall with the controller yet


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## Randall Ave (Oct 29, 2014)

Chevy correct? Between the brake master cylinder and the left side fender there is a dimple in the firewall. That's where I used to drill and go through. But you have to be careful as there are wires just inside the cab there.


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## 2old2shovel (Nov 15, 2020)

I installed the plows mount, and the joystick first. Then I started installing the wiring harness and tested the headlights and here we are. I see a big rubber grommet beside the brake booster Im gonna try and get through that i guess. 

Ya its a GM Sierra. Its an older one, a 2000 but this truck has been oil sprayed yearly and Im none too flexible nowadays so this is a bear of a job for me. I can hardly get under the dash to see and when I try I cant see dang thing my eyeballs are lousy too. Getitng old sucks boys

I'll check for a dimple its hard to see its all black sludge, but it aint rusty! Thats rare for one of these old trucks


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## 2old2shovel (Nov 15, 2020)

oh damn i wrenched my back. Thats all for today thanks for the help guys I think I see a spot I can drill through


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## 2old2shovel (Nov 15, 2020)

Back at it today. Seems these days its pretty dang tricky to source a quality grommet. So I made my own. I had some Ford OEM oxygen pump hose kicking around which is high quality and was just a hair over 1" OD and I had these flat O-rings kicking around so I sliced a 4" section or so off the Ford rubber hose and split it length wise then after wrapping over the harness I used krazy glue to glue it back together then krazy glued these o-rings to the hose both inside and outside which I slid over, no splitting of those. Used a step drill to make a 1" hole and had to ream it a little with a sand paper roll on a die grinder. Some harness tape to the loom and grommet and shes in good and safe now.


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## Randall Ave (Oct 29, 2014)

2old2shovel said:


> oh damn i wrenched my back. Thats all for today thanks for the help guys I think I see a spot I can drill through


Thats every day here.


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## cwren2472 (Aug 15, 2014)

2old2shovel said:


> Back at it today. Seems these days its pretty dang tricky to source a quality grommet. So I made my own. I had some Ford OEM oxygen pump hose kicking around which is high quality and was just a hair over 1" OD and I had these flat O-rings kicking around so I sliced a 4" section or so off the Ford rubber hose and split it length wise then after wrapping over the harness I used krazy glue to glue it back together then krazy glued these o-rings inside and outside which I slid over, no splitting of those. Used a step drill to make a 1" hole and had to ream it a little with a sand paper roll on a die grinder. Some harness tape to the loom and grommet and shes in good and safe now.


Damn, 140 words just to_ describe_ the process needed to _make _a grommet. Good thing I stay behind the counter and don't have to do real work.


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## cwren2472 (Aug 15, 2014)

Randall Ave said:


> Thats every day here.


You left your walker over behind the Snap-On cart.


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## 2old2shovel (Nov 15, 2020)

Well you know how it is, most of the stuff we can buy these days is garbage and maybe this will help some other fella who wants to make a good fireproof safe connection through his trucks firewall, once. I sure as heck dont want to be doing this twice my shoulder neck and back are all twitchin. Buna type rubber glues extremely strong with krazy glue for those that didnt know. Done right you cannot pull it apart


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## Randall Ave (Oct 29, 2014)

cwren2472 said:


> You left your walker over behind the Snap-On cart.


You coulda helped last night with the frame install!!!:weightlifter:
MJD, I need an Old Guy emogee thing. For the over 60 crowd.


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## cwren2472 (Aug 15, 2014)

Randall Ave said:


> MJD, I need an Old Guy emogee thing. For the over 60 crowd.


What would that be? Like, a Grim Reaper? Over-the-hill balloon? Depends diaper?


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## 2old2shovel (Nov 15, 2020)

Made a custom mount for the joystick too. Wanted to operated it with my arm relaxed as if I was cruising down the highway so I positioned it right in front of my arm rest. Put some threaded inserts into the console base to bolt it too and the base for the joy stick is removable so the cup holder can slide over the piece oaf angle. Made for a fairly neat job. Materials all 1/8" thick sheet metal and 1" by 1/8" angle


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## cwren2472 (Aug 15, 2014)

2old2shovel said:


> Made a custom mount for the joystick too. Wanted to operated it with my arm relaxed as if I was cruising down the highway so I positioned it right in front of my arm rest. Put some threaded inserts into the console base to bolt it too and the base for the joy stick is removable so the cup holder can slide over the piece oaf angle. Made for a fairly neat job. Materials all 1/8" thick sheet metal and 1" by 1/8" angle


Nice work!


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## Randall Ave (Oct 29, 2014)

cwren2472 said:


> What would that be? Like, a Grim Reaper? Over-the-hill balloon? Depends diaper?


HA HA HA, funny guy, you will be old to one day.


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## Randall Ave (Oct 29, 2014)

cwren2472 said:


> Nice work!


Looks good, I had one of those, bulky, but worked.


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## 2old2shovel (Nov 15, 2020)

Too soon we get old, too late we get wise. It goes fast, enjoy the ride and do jobs once and do em right. Nothing worse than being outside freezing your sack off buried in salt and slush fixxin a crappy repair/install



> Looks good, I had one of those, bulky, but worked.


Ya seems to work pretty good this thing. I use what I have most of the time and this is what I have so I make it work


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## cwren2472 (Aug 15, 2014)

Randall Ave said:


> HA HA HA, funny guy, you will be old to one day.


Don't worry - I already got a back stretcher thingy. It gets a lot of use.


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## 2old2shovel (Nov 15, 2020)

So Im back at the plow harness again here and the plow side connector has two pins broken off. 

Any ideas on how to repair those pins?


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## 2old2shovel (Nov 15, 2020)

Im contemplating ditching the high beam and park/run circuit Pin 9+12 to accommodate. Light common has me a little cornfused. Running my buyers products lights Id like to use the Curtis quick connect harness pins; 13+14 for left right signal, pin 9 for low beam headlight, rre-purpose the high beam pin 11 for float and park/run pin 12 for for light common but how do I connect that common to both left/right headlights?


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## Randall Ave (Oct 29, 2014)

Storks snow plows has repair ends for the multi pin plugs, you cut off the old plug and wire in a new one per the color coded wires. $60.00 buckes each, replace them both.


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## cwren2472 (Aug 15, 2014)

If you are going to change both ends, since the Curtis stuff is basically obsolete you can also opt to switch to different plugs from another plow. Fisher/Western offer 12 pin plugs and Boss has 13 pin. I think the boss ones would be cheaper than the Curtis, particularly if you have a local boss dealer. That would also make them more readily available should you need to switch them again


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## Randall Ave (Oct 29, 2014)

cwren2472 said:


> If you are going to change both ends, since the Curtis stuff is basically obsolete you can also opt to switch to different plugs from another plow. Fisher/Western offer 12 pin plugs and Boss has 13 pin. I think the boss ones would be cheaper than the Curtis, particularly if you have a local boss dealer. That would also make them more readily available should you need to switch them again


I think the Boss and Curtis ends are almost identical, unless my old guy memory is failing me.


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## cwren2472 (Aug 15, 2014)

Randall Ave said:


> I think the Boss and Curtis ends are almost identical, unless my old guy memory is failing me.


I noticed that - they do look very similar but I don't know if they would actually interchange. At least the socket end appears to be missing several holes and it's not the same missing holes that boss leaves out.


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## Randall Ave (Oct 29, 2014)

cwren2472 said:


> I noticed that - they do look very similar but I don't know if they would actually interchange. At least the socket end appears to be missing several holes and it's not the same missing holes that boss leaves out.


Your going to shoot me. As long as you have an Ohm Meter, and just a little wiring common sense, you can make any thing work.


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## cwren2472 (Aug 15, 2014)

Randall Ave said:


> Your going to shoot me. As long as you have an Ohm Meter, and just a little wiring common sense, you can make any thing work.


Not necessarily- the even though there are 15 positions, boss only has pins in 13 of them. And the 13 they use arent the same 13 as Curtis so you'd lose at least another 2 pins. I'm not sure how many Curtis actually requires but there is no way to add the missing sockets or pins that aren't already there.

Though now that you mention that, the colors are guaranteed to be different, so changing just one end would require a lot of test light/multimeter work to line up


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## Randall Ave (Oct 29, 2014)

cwren2472 said:


> Not necessarily- the even though there are 15 positions, boss only has pins in 13 of them. And the 13 they use arent the same 13 as Curtis so you'd lose at least another 2 pins. I'm not sure how many Curtis actually requires but there is no way to add the missing sockets or pins that aren't already there.
> 
> Though now that you mention that, the colors are guaranteed to be different, so changing just one end would require a lot of test light/multimeter work to line up


That's what makes it a challenge. And keeps guys like me in business.


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## cwren2472 (Aug 15, 2014)

Randall Ave said:


> That's what makes it a challenge. And keeps guys like me in business.


No argument there :laugh:


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## 2old2shovel (Nov 15, 2020)

Ya this is a pain. I had it in mind to wire it up using the curtis plug and re-purposing the pin assignments but the relay pack and common circuits Curtis used has me unsure. I need all 15 pins so swapping to another brand plug wont solve that. I'm thinking of just adding a flat four trailer plug for the extra leads and sticking with the Curtis plug I have for two reasons; 1. As it sits the plow functions 100% perfectly and I dont like to mess with success 2. Cheap, easy, and I have a flat four here I can quickly use. I do appreciate the replies gents, you have been very helpful


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## 2old2shovel (Nov 15, 2020)

Well dang it all. I had it, for a moment I had it. I added the flat four trailer plug as I mentioned earlier and I tapped into the headlight feeds on the drivers side for power which was a mistake. Now I have all four truck headlights on very dim. I disconnected the plow light taps so we are now back to stock OEM truck headlight wiring and the pass side low beam is working properly, but the other three headlights are all stuck on very dim. 

I learned my lesson twice over now DONT mess with the stock headlight feeds. Now how do I go about getting them to work normally again?


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## 2old2shovel (Nov 15, 2020)

Well I seem to have things working as per norm again. I have no idea what worked because I spent the last 30mins plugging and unplugging headlights in, swapping bulbs side to side, pulling relays and swapping around and so on then it suddenly worked as it should. Lets hope it stays that way, good grief


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## Randall Ave (Oct 29, 2014)

As we used to say here, Its a Curtis.


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## 2old2shovel (Nov 15, 2020)

Progress. I managed to simplify my wiring and get all light functions we worked through the Curtis main plug using only 13 pins, all functions as it should now plows working good.

When I bought the plow the jack had never worked. There is a harness plug hanging out of the assembly I just figured needed to be plugged into something. Now I have no idea what this plug is for? I've attached a pic so you can see the plug and the small toggle switch which should be for the jack. Before I start digging in too far whats this plug all about?


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## Randall Ave (Oct 29, 2014)

Go to pages 55 and 56, as they say, its in the book.


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## 2old2shovel (Nov 15, 2020)

I was looking at those pages and am still confused. Is this plug for a v plow? Do need that jumper on it for the jack to work?


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## Randall Ave (Oct 29, 2014)

Depending on what you have is what what used, yours would be for that blankedy blank jack leg switch.


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## 2old2shovel (Nov 15, 2020)

I see. So I have a blankety blank switch at the best of times. Hmmm well I’m still really needing to figure this thing out. The switch in the pump housing has spade leads plugged into it which is why this extra harness plug I posted the pic of confused me. What I want to do is eliminate this plug altogether if its not needed why keep it?


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## 2old2shovel (Nov 15, 2020)

Looks like the plug is there just to make the harness adaptable between the v and straight plows. To get the jack to work requires a diode and that’s what the jumper plug is all about. Starting to narrow in here


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## 2old2shovel (Nov 15, 2020)

Guys why is that M3 plug there? This is a straight blade and I dont see why that plug is even needed or what its for? Can someone enlighten me here?


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## Randall Ave (Oct 29, 2014)

2old2shovel said:


> Guys why is that M3 plug there? This is a straight blade and I dont see why that plug is even needed or what its for? Can someone enlighten me here?


As far as I know, that is not used on your plow configuration. That's why Curtis called it a universal harness.


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## 2old2shovel (Nov 15, 2020)

Thats what it looks like so Im gonna clean it out of there entirely. I still havent got the jack to work but Im a tad nervous going any deeper into it in case I mess up the plows operation. Im working on a scissors jack with a plate base and a bracket Im welding onto it that will hold up against the curtis jack arm and use a cordless impact to zip it up and down for install and removal. Its not ideal, but it should work. Thanks for the info


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## 2old2shovel (Nov 15, 2020)

Removed the plug and left it wired as it was with the splices intact and whatnot. Allowed me to wrap the harness up with corrugated conduit and tape it up good. Scissor jack with a big flat base and a small piece of 2.5" channel to hold around the jack arm is now the "quick jack" solution. Use an electric impact to zip it up and down. Works pretty dang well too. So I guess the fat lady is singing on this plow project thanks for all the help gents. Happy shoving this winter


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## 2old2shovel (Nov 15, 2020)

Well now ive done it. I was sifting through the craiglist ads and found another sno pro 3000 thats in really really good condition. Miles better than the one i already have and the price was good so i bought it today. I hooked it up to my truck in about a minute and up she went, side/side all good so i pay the man and off i go. Now i get it home and i cant drop it! The float does nothing lol so i have a plow stuck in the max lift position on my truck in the middle of summer. Im sure my fancy repin work earlier is the cause and i will go over it all but for now i need to get this plow down and off my truck so i want to pull the 15 pin connector and jumper this thing to get it down. Anyone know what pins i connect to do this?


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## Randall Ave (Oct 29, 2014)

2old2shovel said:


> Well now ive done it. I was sifting through the craiglist ads and found another sno pro 3000 thats in really really good condition. Miles better than the one i already have and the price was good so i bought it today. I hooked it up to my truck in about a minute and up she went, side/side all good so i pay the man and off i go. Now i get it home and i cant drop it! The float does nothing lol so i have a plow stuck in the max lift position on my truck in the middle of summer. Im sure my fancy repin work earlier is the cause and i will go over it all but for now i need to get this plow down and off my truck so i want to pull the 15 pin connector and jumper this thing to get it down. Anyone know what pins i connect to do this?


It will be a little messy but, being very careful and stay away from the plow. If you have a floor jack, put it under the plow. If you can jack it up high enough, remove the chain. If you can't, crack loose the hose at the lift cylinder and the plow should come down. Have some rags handy and do it where if you get some fluid on the ground it won't hurt anything.


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## 2old2shovel (Nov 15, 2020)

Got er all fired up and ran it today for the first time. Funny thing with cutting edges, you kinda forget how good a new one works until you put a new one on. This thing scrapes clean back drag in one go. It runs a little slower than my first one though, maybe the motors not quite as good but it does the trick and looks a heap load better than my old beater which still performs flawlessly. Considering the troubles my brother has had with his similar vintage red plow, I dont know if Im just lucky or if these Curtis plows are really good. Either way happy not to be shoveling although the back is a million times better this year. No clue why, nothings changed it just got better after 5 years of looking like a Robaxacet commercial. Stay safe out there fellas


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