# No Passenger Side Plow Light



## scottymo (Nov 28, 2017)

Hook up plow, have drivers side plow light and Both passenger and driver side marker lights. The passenger side light on my truck stays on, does not switch to plow light. 2005 Chevy Silverado, Ultra Mount Western Plow. Help!!!


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## kimber750 (Sep 19, 2011)

New install? Bad/damaged harness, bad module, hooked up wrong, someone unplugged harness.


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## scottymo (Nov 28, 2017)

original install. Harness is good, hooked up good, and still plugged in. Module maybe? What would I look for and where is it located?


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## dieselss (Jan 3, 2008)

Light plug configured wrong maybe 
Flip the connector from A to B or vice vers


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## dieselss (Jan 3, 2008)

https://www.plowsite.com/threads/no...50-with-3-plug-mm-2-one-headlight-out.171957/


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## Mr.Markus (Jan 7, 2010)

dieselss said:


> https://www.plowsite.com/threads/no...50-with-3-plug-mm-2-one-headlight-out.171957/
> I was wrong in this thread but I'm man enough to have learned from it...


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## scottymo (Nov 28, 2017)

So after further investigation, I found these connections on the passenger side of my truck, all unplugged. I put 2 and 2 together and remembered I hit a deer last summer and the body shop replaced passenger side lights on my truck. I'm thinking they unplugged these connections and they were tucked underneath behind the bumper, that's why I never saw them. They all come out of the same harness so I find it hard to believe that they all go into each other. Where do they all go!!??


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## Randall Ave (Oct 29, 2014)

They plug into your headlamp bulbs. The headlamp plug ends go into those female connectors. They should only fit one way, look inside the plugs for the alignment slots.


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## scottymo (Nov 28, 2017)

Thanks, tried plugging them all in but didn't work. Of course from being shoved behind the bumper for 6 months both male and female connectors are badly, badly corroded. So I'll go get some new connectors and start with that. I will keep you updated, thanks for the replies.


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## Randall Ave (Oct 29, 2014)

Your not like around here are ya, I do think I have some of those here. When you replace those ends, use heat shrink ends. And make sure the wire will not pull out of the crimps.


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## scottymo (Nov 28, 2017)

Unfortunately I'm in upstate NY by Rochester but there is a plow dealer about a half hour away. Appreciate your help!


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## kimber750 (Sep 19, 2011)

scottymo said:


> Unfortunately I'm in upstate NY by Rochester but there is a plow dealer about a half hour away. Appreciate your help!


You need to unplug the connectors from your truck lights. Take those and plug into the two female connectors in the pic. Take the two male connectors and plug them into your truck lights. You will need to look up which is for high and low beam because I can't remember right now.


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## leolkfrm (Mar 11, 2010)

did you stay hooked to the plow to check them after connecting? need to for the module to switch lights


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## scottymo (Nov 28, 2017)

Kimber750: I did
leolkfrm: I did

As I said, the connectors are corroded beyond saving so I'm on my way now to get new ones. Will report back once I get them on.


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## scottymo (Nov 28, 2017)

OK, so put the new connectors on and everything is plugged in where it is supposed to go. BUT, the headlight on the truck still stays on and it does not switch to the plow light. One good thing is that now I know the connectors work because at least the truck light comes on. Where to next?


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## leolkfrm (Mar 11, 2010)

follow the wires and see if they may have pinched or damaged on

maybe run a continuity test on wires from connector to module


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## Philbilly2 (Aug 25, 2007)

switch a and b on your isolation module and see if you have the same issue or if it switches to the drivers side


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## Randall Ave (Oct 29, 2014)

Look at the other side, that will show you what goes where.


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## scottymo (Nov 28, 2017)

Philbilly2 said:


> switch a and b on your isolation module and see if you have the same issue or if it switches to the drivers side


Where is the isolation module usually and what does it look like?


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## kimber750 (Sep 19, 2011)

Post a pic of what you have connected.


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## Philbilly2 (Aug 25, 2007)

scottymo said:


> Where is the isolation module usually and what does it look like?


It is a black box that says a,b,and,c on it. With 3 looms of wires coming out of it.

It will be somewhere under the hood. Every person mounts them in different locations


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## scottymo (Nov 28, 2017)

Philbilly2 said:


> It is a black box that says a,b,and,c on it. With 3 looms of wires coming out of it.
> 
> It will be somewhere under the hood. Every person mounts them in different locations


Just doing some research online looking at some schematics, shouldn't I swap B and C? Don't be offended, because I know that you know way more than I do, but just trying to understand it all.


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## scottymo (Nov 28, 2017)

Scratch all that. Just crawled under the truck and found that I do not have an isolation module. I have a relay system. Also, I can not find the schematics for my setup. I have a 12 pin setup, but the only schematic I can find is a 12 pin, 3 relay. I have 6 relays. So now what???


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## Philbilly2 (Aug 25, 2007)

A two plugger on a 2005?

I don't have my wiring books at home, but if someone has not lead you to the correct relay by Monday.


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## scottymo (Nov 28, 2017)

So I have an oddball setup? Was there not alot of 2 plug setups?


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## dieselss (Jan 3, 2008)

http://library.westernplows.com/doc...ename=22373.07_110108_for_web.pdf&doctype=pdf

Should be all the diagrams


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## Randall Ave (Oct 29, 2014)

Your going to have to get a wiring diagram off the Western site. You may have corroded connections at the relays, or bad relays. If you start pulling wires off, mark them somehow.


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## Philbilly2 (Aug 25, 2007)

scottymo said:


> So I have an oddball setup? Was there not alot of 2 plug setups?


No, it is a completely normal set up from the 90's.

Right around 2002 they were fazing out the 2 plug really system and going to a 3 plug with an isolation module. That was also when gm went from positive common to negitive common or vise versa.

It is just odd to see a two plug ultra as it always seems that i am the only person that still had any of them


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## scottymo (Nov 28, 2017)

ok, so this is what I have. So I'm thinking Relay #1 & Relay #2 are bad? Instead of sending power to terminal 87, it's sending power to 87a. I came to this conclusion since my truck lights are staying on. Let me know what you guys think.


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## Randall Ave (Oct 29, 2014)

Did you check if the suspect relays are getting power and ground to the control terminals, 85 and 86 if I remember right.


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## dieselss (Jan 3, 2008)

Pwr and gnd at 85 and 86 of relay 2?


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## scottymo (Nov 28, 2017)

I believe 86 is getting power because my parking & signal lights are working on the plow and 86 is what goes to them. The problem is this had to of been an install at 4:59 pm when the guys at the shop were getting out at 5:00 pm. All of the relays are shoved behind the driver side light, in front of the battery. It is the truly the definition of a "rats nest". So in order to check anything (connections, broken wires, etc...) the only way I can check them out is to pull the battery. There is literally no room to work whatsoever. So checking for power is going to be a tall task.


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## Randall Ave (Oct 29, 2014)

Don't ever assume something has power and ground. You have an DVOM? And there basic relays, any auto parts store should have them.


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## scottymo (Nov 28, 2017)

Randall Ave said:


> Don't ever assume something has power and ground. You have an DVOM? And there basic relays, any auto parts store should have them.


I'm not assuming, I'm just saying that to get to the relays, I HAVE to pull the battery, and if I pull the battery, how do you check for power? I will post a pic later of what I'm talking about, it really is bad.


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## scottymo (Nov 28, 2017)

so let's just say, theoretically, 86 would have power because the parking lights are on, correct?


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## dieselss (Jan 3, 2008)

Need to actually check the pins, but they could still be corroded.
Look at the blk/org ground wire, that comes off the plow and grounds the relay out.
See if you can just use a jumper wire from ground right to that relay.


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## Western1 (Dec 4, 2008)

Isn’t it easier to get at it pulling the headlight out? Just one pin


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## scottymo (Nov 28, 2017)

Which terminal do I go to, 85?


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## scottymo (Nov 28, 2017)

Western1 said:


> Isn't it easier to get at it pulling the headlight out? Just one pin


Nope, tried that first


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## dieselss (Jan 3, 2008)

scottymo said:


> Which terminal do I go to, 85?


For ground, yes 85......looks to be blk/org wire that's coming off the other relay. When checking, need to have the plow plugged in


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## scottymo (Nov 28, 2017)

Well, project has to go on hold. My grandfather died so I'm taking off for California Monday. So I'll get back into this next weekend and update you guys on my progress. Thanks again for all your help.


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