# Curtis SnowPro 300 - lift/angle issues



## letitsnow10 (Oct 8, 2014)

Good Afternoon All,

My apologies in advance for the below dissertation, but I wanted to paint the picture as best I could for everyone.....

I have a Curtis SnowPro 3000 that is the old style (single plug) that is at least 10+ years old. The plow functioned excellent for me 5 years with little maintenance completed to during that time except for the draining and refilling the hydraulic fluid. The plow has been sitting for the past 5 years, 4 of which were outside, and covered. The plow is now inside my garage and I would love to get it back into shape to use this winter.

I have since put the plow on a new-er truck (2005 GMC Sierra 1/2 ton) than what it was originally on. I purchased a used truck side wiring harness (old style) and new headlight adapters. I plugged the plow in and NOTHING happened except for the clicking of the solenoid. I figured it was a bad ground and decided to clean both connections on the dual post 12V motor and wire connectors. While taking the ground off, I noticed that the post was spinning. The nut holding the connection was cross threaded on, and from being 10+ years old was rusted so bad that before I could notice what had happened, the post was spinning. Eventually the post broke and I removed the motor from the frame to find the internal wires inside the motor were destroyed from spinning the post so much. I purchased a new 12V single post motor that the parts person said was compatible and installed it. There was a change.. Now I heard the existing clicking of the solenoid AS WELL AS the new motor spinning with NO plow functions.

I then got the tester light out and made sure that I had power going to and from the following: the battery to the controller, battery to solenoid, controller to truck side plug, controller to solenoid, controller to the float/lift/center/angle and jack valve solenoids. I also tested the grounds and they were good. The solenoids did magnetize when the controller pad was being pressed on that particular function. All of the exposed wires looked intact and were not damaged.

Next, I drained the hydraulic fluid which looked like watered down milk... Obviously, some water had gotten in there somehow - probably just from use before I stopped plowing for those 5 years... The screen did have some foreign objects surrounding it and the magnet did its job because anything metallic stuck to it. I refilled the reservoir with new hydraulic fluid and attempted to lift/angle the plow but again, no movement occurred. The solenoid was still clicking and the motor was still spinning. 

I then tried to give the plow a little assistance (plow appears to be in the float position with NO angle) in angling, for it was not angling at all. To assist, I did the following: Hooked the plow up to the truck, made sure my connection was good, hooked a come-a-long to the right side of the plow and attached it to the tow hook of my truck, while hitting the angle right arrow I tensioned the device (in hopes of freeing the plow). 
The solenoid was clicking, the motor was spinning and eventually, the hydraulic line going to the right angle valve burst from the pressure of the tension. 

I drained the reservoir again as well as disconnected all of the hydraulic hoses (which then allowed me to angle the plow in any direction by hand). I had new hydraulic lines made, installed them and refilled the reservoir with new hydraulic fluid. I then tried the functions of the plow while hooked up to the truck and again, the solenoid clicked, motor spun and the plow raised up approximately 4" off of the ground - that's it. Still no angle left/right function. The noise that is made and heard from the motor/pump is NOT the same as I remember. The motor/pump sound as if they are both struggling to lift the blade....

I have a new dual post 12v motor that is recommended to replace the motor from the manufacturer on order as well as a new float valve. 

Does anyone have any ideas on what could be the issue? I am at a standstill until these 2 items reach my garage and when they do, I am not optimistic that they will fix the issues that I am having. Any thoughts will help. I greatly appreciate it...

Bart


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## dieselss (Jan 3, 2008)

Try this yet?

http://c0403621.cdn.cloudfiles.rack...Diagnostic_Troubleshooting_Guide-72-520-1.pdf


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## Randall Ave (Oct 29, 2014)

When you installed the new motor, did you have the coupling on the shaft?
I haven't played with one in a while but there should be a coupling. 
If it has sat as long as you say, take the tank off and remove and clean the pick up screen.


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## letitsnow10 (Oct 8, 2014)

Dieselss - Thank you for your reply... Is the link you sent the troubleshooting guide? Was there anything specific in the guide that I should look at? I have gone through it a few times but will take another look at what you are referring to. 

Randall Ave - Thank you for your reply... This plow was purchased from Roe and Co and you folks may have installed in on my other truck years and years ago. It worked fantastic up until 5 years ago before it sat... Thanks for the good work you did... As far as when I installed the new motor, I did place the coupling back on the shaft(s). I did remove the tank, drained it, cleaned it out, cleaned off the magnet and pick up screen to no avail.. Any other thoughts?


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## Rick547 (Oct 9, 2009)

I think I would pull the valves and clean each of them plus the manifold block.


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## letitsnow10 (Oct 8, 2014)

Rick - Thanks for your response... To clean the valves, would I use a rag and some brake cleaner? Also, how would I go about cleaning the manifold block? Splitting it?


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## Randall Ave (Oct 29, 2014)

Does the motor sound like its spinning fast enough? You need to remove the lift hose and put a pressure gauge on end of the hose. Should have around 2000 lbs. That's your next move. 
What year was the install?


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## Randall Ave (Oct 29, 2014)

If you raise the plow, remove both hoses, can you push the plow back and forth?


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## letitsnow10 (Oct 8, 2014)

Randall Ave - When the hoses were off, I was able to push the plow back and forth. Have not tried since I put the new hoses on. I'm not 100% sure if the motor is spinning fast enough... It doesn't sound like it sounded years ago... As far as the pressure gauge - does that go in line?


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## Rick547 (Oct 9, 2009)

letitsnow10;2059830 said:


> Rick - Thanks for your response... To clean the valves, would I use a rag and some brake cleaner? Also, how would I go about cleaning the manifold block? Splitting it?


I'm not hyd expert. I would be reluctant to use brake cleaner as it could effect the seals. I would just remove them and look of rust and debris. The value should move freely and not stick. With all the water sitting in the fluid over the years the plow was idle. I would think you have stuck had solenoid valves. Just my two cents.


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## Randall Ave (Oct 29, 2014)

letitsnow10;2059845 said:


> Randall Ave - When the hoses were off, I was able to push the plow back and forth. Have not tried since I put the new hoses on. I'm not 100% sure if the motor is spinning fast enough... It doesn't sound like it sounded years ago... As far as the pressure gauge - does that go in line?


You would remove the hose from the lift cylinder. Connect a pressure gauge into end of hose. You may have to take the fitting out of the lift cylinder. Get a female pipe nipple to connect your gauge to it. Its probably 1/4 pipe. You need a 5000 gauge, that's what I use.


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## letitsnow10 (Oct 8, 2014)

could you send a picture of you wouldn't mind?


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## Randall Ave (Oct 29, 2014)

letitsnow10;2059913 said:


> could you send a picture of you wouldn't mind?


I will have to see if I have anything in pics at the shop tomorrow. Rowes is out of business, so I do not see Curtis stuff much anymore. 
What I have told other people, you can find Curtis stuff used cheap. If you can find a used plow, get it and use parts off it.


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## Randall Ave (Oct 29, 2014)

Sorry, do not have any pics of Curtis plows. Remove the hose from the lift pistion, install a pressure gauge into the end of the hose. Hit the lift function, read pressure.


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## TJS (Oct 22, 2003)

Is this a fenner pump. Post a pic of the pump assembly. That PDF is huge so I stopped downloading it. I have a modified fenner pump with a larger CC pump and increased my pressure spring to the 3000+ psi one. Post a pic.


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## letitsnow10 (Oct 8, 2014)

I ordered a new float valve kit and replaced that this morning... Still no change.. I am working on getting a pressure gauge to put on the lift hose to make sure I have sufficient pressure. In the meantime, could the fixed relief valve be stuck in the open/closed position? The plow will lift off the ground 4" but will not go down into the float position or angle left/right.... Once I disconnect the hose from the lift cylinder, hydraulic fluid shoots out and the cylinder retracts just from gravity/tension from the lift chain. I'm thinking there is a stuck relief valve somewhere in the manifold assembly....

Any thoughts?


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## TJS (Oct 22, 2003)

letitsnow10;2065348 said:


> I ordered a new float valve kit and replaced that this morning... Still no change.. I am working on getting a pressure gauge to put on the lift hose to make sure I have sufficient pressure. In the meantime, could the fixed relief valve be stuck in the open/closed position? The plow will lift off the ground 4" but will not go down into the float position or angle left/right.... Once I disconnect the hose from the lift cylinder, hydraulic fluid shoots out and the cylinder retracts just from gravity/tension from the lift chain. I'm thinking there is a stuck relief valve somewhere in the manifold assembly....
> 
> Any thoughts?


Tell us the pressure first and then we can give you more thoughts. Are you 100% sure you are not commanding the down valve the same time you are trying to lift the plow.


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## letitsnow10 (Oct 8, 2014)

So today I made up a pressure gauge to read the lift pressure... It was 800psi, not nearly close to the needed 2000psi.... 

Took the pressure relief cartridge out of the manifold to check the spring, needle, etc. and everything looked good. Also, removed the lift cylinder hydraulic hose from port "H" on the manifold and that looked clear (even put a small piece of wire in the "Orifice" to clean it out). Everything went back on (reservoir, pump, drain hose, lift hose, suction screen and tubing) and then proceeded to check to make sure proper voltage was present... At the float solenoid/valve, 4volts were present (not the 12v needed). The lift function had 11volts (I'm ok with 11v). The truck side harness connection for the float function (green wire) was at 4-5volts (not the needed 12v). All of the other connections had the necessary 12volts. The controller for the green wire had 12volts. The connection on the wiring harness just in front of the connection for the controller had 12volts. I'm thinking that I have a bad green wire somewhere between the connection on the wiring harness where the controller connects to and the connection to the plow side wiring harness.... Thoughts?

Am I correct in thinking that the float function and lift function are operating AT THE SAME TIME as each other? One needing to be open and the other being closed depending on if the plow is being lifted/lowered/float?

Thanks for your input everyone!
Bart


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## TJS (Oct 22, 2003)

Bart,
That is what I was referring to in my post #17. You have to take the down/float command out of the equation. Disconnect the wire going to it and then try the up function. I am not to familiar with Curtis controllers but do they use a circut board and if they do a 4v or 5v reference is used as in many automotive ECM's. This is why I build my own wire harness and simple up down left right toggles. This way if something goes wrong it is easy to fix.


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## P/EEZ (Nov 10, 2004)

Hello Bart
Sorry u r havg these issues/ I just went thru same issues w/ plow pump spinning and no lift left or right or float/but u could hear solenoid clickg to spin pump/ figured it was a ground issue.
I had just cut off my single molded plug 3" back from truck side plug and spliced in the newer 2 plug setup/ still not enough voltage going to plow/ checked all wires on male pins (truck side molded plug) and guess what!
There was no ground on the orange wire/There must B Ground @ the orange wire/
My solution was to splice into the orange wire and run to ground or the frame rail, about a 12" ground wire/ 
Everything operates as it should now/ I have 2 plows w/ 2 plug setup and both were exhibiting same issues so I figured it had to B truck side wiring/ Good Luck


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