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Unimount - motor does not run

Discussion in 'Western Plows Discussion' started by Al Thorp, Dec 16, 2010.

  1. Al Thorp

    Al Thorp Junior Member
    Messages: 12

    I have a Western Unimount Plow on our Dodge Ram 1500. I don't know the age of the plow offhand, but I know it is equipped with the Isarmatic Hydraulic System. Over the last couple of years, the plow has worked intermittently. I use it to plow the driveways on our farm - I don't plow commercially.

    Usually, the pattern I have observed is that when I first attempt to raise the plow, it doesn't respond. Voltage has typically dropped during this first period of time when I'm actively pushing the lever to raise. I have been able to see this on the voltmeter, and also on various lights on the dashboard which dim. Usually, if I keep at it for a while, the pump will at some point instantaneously spring to life, and then there are usually no more problems for that day. I know it is pathetic that I haven't addressed the problem until now, but....

    This morning, I went through the same procedure, only this time, there came a point where there was still a clicking noise which I heard upon pressing the lever to raise (solenoid?). But, no associated voltage drop at the same time. Time to get out the manual.

    I went to Western's website, and obtained a copy of the Mechanic's Guide for the Unimount Snowplows, which was very helpful. I went through the nine basic checks, and cleaned the terminals at the battery, checked my ground, etc., then as none of that improved, I proceeded with the Motor Test, by hooking up a pair of jumper cables directly from the battery to the terminals on the motor.

    Result - the motor did not run. Not at all.

    The diagnostic chart indicates that I should "Check for binding in pump. Replace pump, or repair or replace motor."

    But I could not find any more information in this manual or on the Western Plows site about how to perform these steps. Can someone direct me to a service manual of some kind that addresses how to do this?

    Also, based on what I've written, can anyone suggest what might be wrong and the most cost and time effective way to solve it?

    Thank you in advance for any suggestions!

  2. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    When you hook up the motor directly, you did make sure the "ground "cable was on there good??

    If the case was the motor is bad, REPLACE it..

    While your at it, replace the fluid, and while the motor is off, check the suction screen to make sure it is nice and clean. If your not sure on how to change the fluid, here is a link..Look at post #3

    As for a power lost.. If I am correct, the plow motor will draw between 150-200 amps (I am pretty it is in that range).

    I would think about going to "dual" batteries". I would use the second battery for the plow only. I don't know what kind of vehicle you have, on my vehicle, I change the charging wire (the "BAT" wire off the back of the alt) to a 10 gauge., and also install a second battery..

    Let us know how you made out..
    Last edited: Dec 16, 2010
  3. no lead

    no lead PlowSite.com Addict
    Messages: 1,308

    if you put cables to the motor and it didn't run i would suspect it is bad. unbolt the motor and see if the pump shaft will turn freely. if it does the motor is bad. if the pump shaft wont turn the pump is locked up and wont let the motor turn.
  4. Al Thorp

    Al Thorp Junior Member
    Messages: 12

    Motor is off

    Yeah, I was thinking it was possible that I didn't have a great connection to the motor with the jumper cables, so I double checked the diagnosis by checking the voltage at the motor terminals while my son pressed the lever to "raise". 14.3 volts. The voltage is getting to the terminals of the motor, but the motor is not doing anything.

    Twinman, thanks for the suggestions to perform the other maintenance while the motor is off. Great ideas.

    I'm going to buy a new or rebuilt motor and I'll post back after I've re-installed. Thanks for the help!
  5. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    Yes, shoot the motor, and get another one..Make sure you get a new gasket as well.. If your going to change the fluid, I use the "Blue" hydraulic fluid instead of transmission fluid.. I always had better with it instead of transmission fluid..

    Make sure you check the wires on the solenoid as well..Make sure they are clean and making good contact..

    Keep us posted
    Last edited: Dec 16, 2010
  6. Al Thorp

    Al Thorp Junior Member
    Messages: 12

    I've got some good news and some bad news

    The good news is that I picked up a new motor this evening at the local snowplow equipment shop. Removed the hydraulic pump as well, cleaned the filter and replaced the hydraulic fluid. I did get the "blue" EZ pour fluid. Got it all back together, reconnected the wires, and well, here's the bad news.......

    Brace yourself. This is just plain STUPID on my part.

    I knew the black wire goes to the ground terminal on the motor, and I knew the black wire with the red stripe goes to the positive terminal of the motor. But, I was unsure about the small black wire with the orange stripe. I guessed that because it had an orange stripe (similar to red) that it was to be connected to the positive terminal on the motor.

    Not knowing I had made a mistake, I started the truck, attempted to run the plow, and it seemed to work for just a second, and then the lights went dim and it seemed like something was wrong...I wasn't sure what at the moment, so I immediately attempted to shut the vehicle off by turning the ignition key to off. The motor didn't stop running. After a few seconds, I turned the switch on the plow control to off, and the motor stopped.

    I checked my manual, discovered I had connected the wire incorrectly, and repositioned it on the ground terminal of the motor, and after jumping the vehicle, managed to restart it, and alas, the plow works great now.

    But there's one problem. As soon as I take my foot off the accelerator, the truck stalls. And I don't think its because of low voltage at the battery - The truck starts without a jump. And then stalls. I'm thinking I fried something in (perhaps) the primary electrical system....

    Any thoughts for a fool? (take it easy on me...)
  7. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    Ok.........I believe the Dodge trucks have what is call a "TPS". Throttle position switch. Sounds weird, right.. What the TPS does it controls the idle. When it is cold, the computer tell the TPS to increase the rpm as well tell the oxygen sensors to gives more air fuel ratio. When the truck reaches operation temperature, then the computer tells the oxygen to decrease and also telling the TPS to lower the rpm.

    Therefore most likely you damage the TPS, but I don't think the black/orange wire being it is a ground wire for only the plows lights, S valves, and the controller get connected to the solenoid on the small terminal really had anything to do with it. Or less it fed back in the fuse box through the controller. Just in case, I would check to see if any fuses are blown to be on the safe side. That also might fix your problem. Dodge trucks also have fusible links (a wire with a rubber around it). use a test light and test (stab the wire)the link on both sides of the wire to see if you have power. Or look at the link to see if you see a "burn"mark. That will also indicate the link is bad..

    By you keep using jumping cables to jump start your vehicle could have created the problem. They moto is, when using jumping cables, red to the positive, and black to "engine" ground (ground off the engine block) , not to the battery neg terminal ( went to school "sun electronics" for 2 years). There is a lot of confusing in regarding how to jump a vehicle. After you get your truck started and fix your problem with the engine idle, take the vehicle to a auto part store like auto zone, and have them check your charging system. Make sure the alternator is not over charging, or even under charging.They also could plug in a hand held diagnostic into the control module (computer) to see if you have any codes. If there is, they can tell you what part is causing the problem..

    Let us know how you made out.. Good luck
    Last edited: Dec 18, 2010
  8. Al Thorp

    Al Thorp Junior Member
    Messages: 12

    Checked the fuses - all good


    Thanks for your help with this. I checked all the fuses, and they all look good.

    I also pulled out my manual on the 2001 Dodge RAM 1500 pickup, 5.2L V8 engine, and confirmed that it does have a Throttle Position Sensor. It sounds logical that at there is at least one problem at that sensor. I called the local NAPA and they have one in stock, around $58. I think I'm going to try replacing that sensor, and we'll see whether that cures the stalling problem....

    I also have a scan tool that I might use to diagnose further - though, the engine light did not go on....

    Thanks again.
  9. Al Thorp

    Al Thorp Junior Member
    Messages: 12

    Good news

    Before taking off for the parts store, I checked online at the Dodge Forum for discussions about the throttle position sensor, and indeed found several. Apparently the problems associated with the throttle position sensor and the IAC idle air control are interrelated, and difficult to tell which one might be causing the problem.

    But, I found a few threads which suggested that when the battery terminals are disconnected, memory is lost in the Powertrain Control Module (PCM) and that upon reconnecting the battery, the PCM has to relearn its settings, including settings for TPS and IAC.

    I figured I'd give it a try - disconnect the battery terminals and reconnect. Well, good news, the stall at idle has now disappeared. Runs great. As far as I can tell, there's nothing wrong any more. On to the next project! Thanks again for the help!
  10. twinman326

    twinman326 PlowSite.com Addict
    Messages: 1,683

    After I sent you the post, I was laying in bed, and I forgot to say something about the IAC valve, and the battery trick.. It does clear the memory. The IAC also has to do with the TPS as well. On the safe side I still have it check out for codes.. Matter of fact, the temp sensor, oxygen sensor, IAC, TPS all have something to do with the idle

    Glad everything work out for you
    Happy holidays, and safe plowing....