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Older Boss V plow wont raise...

Discussion in 'Truck & Equipment Repair' started by BigJohn, Dec 26, 2006.

  1. BigJohn

    BigJohn Junior Member
    Messages: 14

    First let me say I am new to plowing, and want to add this service to my small business. I have a 1987 GMC full size Jimmy, with, I believe, a first generation Boss V plow.
    My problem started as an electrical problem, and, after getting that fixed, I thought, now the plow won't raise, or wings swing. I was told that it may be a plugged filter, and it needs to be cleaned out, but I don't know where to start. I don't want to blunder into fixing it, and screw it up, but my only other option is to bring it to a local mechanic, and he is pretty expensive. Tried the Boss website, but nothing matched my plow.
    I'm sure the plow will lower, but you can see my problem there. I'd never get it to raise back up.
    The pump wants to work, but all I get is it screaming at me, and my voltage drops severely.
    Any help would be appreciated.
    Thanks,
    BigJohn
     
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Welcome BigJohn! First, if this is an older "Gen 1" Boss plow then the pump unit is mounted under the hood, correct? Since the pump run's in all position's but nothing move's then the first thing I would check is the fluid level in the reservoir. If the fluid level is ok then pull the reservoir tank off the end of the pump and check the pickup tube and filter to see if their plugged.
     
  3. BigJohn

    BigJohn Junior Member
    Messages: 14

    First of all, thanks for the quick reply. I think Plowsite may turn out to be a great place.
    Yes, the pump is under the hood, driver's side. I was going to take off the reservoir side, I can see the four bolts,, but was worried that it may have a gasket on it that may break, and not sure if I would be able to get a replacement. I guess the only way to find out is try. I'm not totally against doing it myself, but wasn't sure of myself. Did get a drawing of what looks like my pump, and it shows where the pick up tube is, so I guess I will just go for it.
    I've included the pdf file of the pump diagram I was able to get, and I would sure appreciate anybody who can tell me what generation, or model plow this is, as it would help with parts identifiying, etc. I will try and get some photo's on here to help identify it.

    Again I thank you, and I'll try and keep you informed.
    BigJohn
    jnl@copper.net
     

    Attached Files:

  4. BigJohn

    BigJohn Junior Member
    Messages: 14

    Here are the pics I said I would include to try and identify this plow. I replaced the solenoid on the motor/reservoir as you can see, and the old one had "91" printed on it. 1991?
    Any help on identifying age and model would be appreciated.
    Thanks again,
    BigJohn

    Plow Truck on 12-26-06 1.jpg

    Plow Truck on 12-26-06 3.jpg

    Plow Truck on 12-26-06 4.jpg

    Plow Truck on 12-26-06 5.jpg

    Plow Truck on 12-26-06 6.jpg
     
  5. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Bigjohn, Your plow setup is the old RT1 series. And judging by the "91" you found stamped on the valve you replaced I'd say the plow was new in 91 or 92.They stopped making them in 94 and switched to an RT2 design but the pump and control system was basically unchanged for years. MOST parts are still available for you plow and hydraulics.It's good you have a diagram for your pump, that will give you a little heads up on what your getting into. Go ahead and pull the reservoir off and clean it out along with the pickup screens.I'd also disconnect the hoses and drain the rest of the system while your at it.
     
  6. TJS

    TJS PlowSite.com Addict
    Messages: 1,346

    I am not a Boss owner but you need to check to the magnetic solenoid/valve assemblies on the valve body assembly. It could be your float down solenoid is stuck and bypassing thus not allowing the fluid to be deverted in the valve body to the lift cylinder. Find the solenoid that does(locate the lines from the lift cyl. to the valve body)this by checking with a test light for power when you call for "down". It looks like the far right one in your last picture. If is has power all the time then you have a wiring/switch problem. It should only have power when calling for "down" This applies voltage to the magnetic coil pulling the needle valve back allowing the fluid to bypass thus letting the plow down. Once you find that one take the back nut off and the coil part slides off allowing you to get to the needle valve nut assembly. Take that off and inspect it. It could have some dirt or something stuck in it or it is mechanically bad. I have a Fenner pump that would not let my plow down, the the float solenoid coil was bad. I got the coil/valve as an assmebly from a Meyer "A" valve set up and it worked on my Fenner valve body with a little machining..of the large nut.
    Hope this helps some.
    T.J.
    www.tjsperformance.com
     
    Last edited: Dec 27, 2006
  7. BigJohn

    BigJohn Junior Member
    Messages: 14

    WOW. I was hoping for a little help, but I never expected this much. Seems like a great bunch of people on here. I thank you all......
    I did pull off the reservoir, and the filters seem ok. Cleaned what I could, put it back together, and refilled it with atf. Guess that wasn't the problem, as it still won't work.
    It's not lowering the plow I have a problem with, it's raising it, and swinging the wings. I haven't tried lowering it up till now, because if I do, and it won't come back up, I'm in worse shape. But the solenoid suggestion, and the draining of the system I will check and do.
    Please stick with me here. As I said earlier, I'm a greenhorn at this, and I'm learning as I go. That is, with a little bit of help from the great people on here!!
    Maybe I'll have this thing working before the snow flies.....
    Thanks again to you all!!!!
    I'll keep you informed.....
    BigJohn
     
  8. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Ok, since the plow is already in the raised positoin your "down/float" solenoid can't be stuck open or it wouldn't hold the blade in the air. But TJS might be on to something. Ok,we know that the motor will run but the blade wont move in any position. Here's what might be the problem, your motor/pump assembly work's so it must have good power and ground. The coils on the valve block have to have ground too in order to operate and each of the coil's have their own ground wire. Bigjohn follow the ground wire's from the coil's,somewhere in the harness all the coil ground's will come together and be grounded somewhere.You could also make up a couple of jumper wire's and run one to each coil as a test.Since none of your function's work I'd bet that's what is wrong.I'd also bet if you tried to lower the blade it won't lower either! Let us know what you find.
     
  9. BigJohn

    BigJohn Junior Member
    Messages: 14

    Thanks B&B. That sounds a little more reasonable. You may be onto the problem. It reminded me that the guy who first worked on this, said there was a black wire just hanging in there, but he had checked it, and said there was no power on either end and he didn't think it had anything to do with it. I didn't think much of it then, he just said it as an afterthought, but I just went out and looked, and I'll be darned, there is a loose wire hanging there. (Remember, greenhorn here, and learning....duhhh) It comes out of a wrapped harness, and up between the solenoid block, and the fender. Why I didn't notice it before, I don't know. Probably concentrating on the reservoir and not paying attention.
    It's kinda late now, and gotta work tomorrow early, so I will check that tomorrow.
    Keep your fingers crossed........
    I'll let you know......

    Thanks again,
    BigJohn
     
  10. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Good luck Bigjohn, let us know!
     
  11. BigJohn

    BigJohn Junior Member
    Messages: 14

    Well, I found the wire. But I think it confused me even more. See if this makes sense.
    It's a black wire (ground?) and, at the solenoid block, it comes out of the harness that comes from the controller in the cab. As it comes out of the harness, it is doubled back on the harness, taped to the harness, and it runs back towards the cab. It is cut,and hanging loose there. The only wire that it could hook to, is also cut off (that end is coming out of the cab), and I traced it back. It's taped to the harness, into the cab, and then goes to an in line fuse holder, and into the fuse block.
    Well, I tried it as a ground, the end coming from the solenoid area, and still no plow movement. Then I connected it to the end coming out of the cab, the one to 12 volts, and still no change, except the blade now dropped.
    You we're right B&B, the blade would not drop before I did this. But now with power to the wire,(I think), It did drop. And to add insult to injury, when that wire was connected, the plow pump worked with the key off and out of the ignition. HUH?????
    I know there has to be a good reason for this, but I don't think I can think of what it is.....
    I included a drawing if you can figure it out.
    8 wires coming out of the harness, one for each solenoid, and the black one.
    I think I'm more confused now, and now my plow is stuck down.......

    BigJohn

    wiring.jpg
     
  12. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    John,it sounds like somebody was chopping on you harness at some point.Thats gonna make this diagnosis tough.Ok, As to the plow working with out the key on,that's no big deal. It's just whatever port you plugged the black wire into in the fuse panel just happend's to be hot all the time.We'll work on that later.BTW the black wire inside the cab with the inline fuse,does it look like it was part of the factory plow harness or does it look like somebody added it? Now all the wire's that you found that were cut,are you positive that their all black? Could one of them be brown? Let me know.
     
  13. BigJohn

    BigJohn Junior Member
    Messages: 14

    I have only found one wire so far that has been cut, and I'm pretty sure that both pieces were black. I will check in the daylight tomorrow again.
    As to the factory/juryrigged question, I think it was factory, but hard to tell under that dash. I'll check that tomorrow too.
    Any idea where I could get a wiring schematic on this system? Would probably help a lot. I'll do some checking on the internet tonight too, but let me know if you would.
    By the way, my wife want's to know if we are getting serious here. LOL......
    I am spending a lot of time on here......
    Wonder what she means, hmmmmm
    Thanks again for spending the time to help me. And anybody else.
    This is starting to become a challenge. A good one though. Hope soon this can be resolved.
    BigJohn
     
  14. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Yea John, diagnosing wiring from a thousand mile's away can be very time consuming and a little confusing. BTW as far as spending a lot of time on here tell you wife it's just "research" LOL. Also,do you have access to a test light? With a test light I think we'll be able to get your system up and running. I printed off the diagram that you drew up and I'll study it a little when I get the chance.
     
    Last edited: Dec 28, 2006
  15. BigJohn

    BigJohn Junior Member
    Messages: 14

    B&B.....
    Hi. This is BigJohn's wife. A girl will wonder when two men hook up via wires.
    Seriously, thanks for all the help you've given him.
    It's kept him out of my hair, seeing as he doesn't have any......
    Lee
     
  16. BigJohn

    BigJohn Junior Member
    Messages: 14

    Sorry about that. She got on here first.....
    I do have a test light, just have to find it. I'll have it tomorrow morning.
    Thanks again. (I do have some hair!!)
    BigJohn
     
  17. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Uh oh, for a minute there I though I was in trouble! LOL :blush2: Geat,if you got a test light were still in business.
     
  18. BigJohn

    BigJohn Junior Member
    Messages: 14

    Hey. Finally got the test light. I've got to get organized someday....
    I thought of something else too. I replaced the solenoid on the pump motor, but when I picked it up at the auto supply (Boss brand), it was quite pricey. When the mechanic who was helping me saw it, he took it right back to the auto supply, and asked for a different one. There was a local repair shop owner there at the time, and I asked him if it made a difference as to which solenoid I used, and he said no it didn't. Wondering if I should have listened to him. What do you think.
    Also the Boss brand had a flat back for mounting, and the generic one was just a regular type solenoid.
    Let me know.
    BigJohn
     
  19. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    As far as the solenoid goes, since your pump motor's operating then the solinoid is working ok, it's your valve's in your valve manifold that dont want too work. BTW did this plow ever work since you had it or did it just recently stop working? Just curoius. Also, not sure why but I can't send you PM's yet. I have a wiring diagram I will send ya for your plow but I need your email address. If I can get a diagran right there in front of you it will make this much easier.
     
    Last edited: Dec 29, 2006
  20. BigJohn

    BigJohn Junior Member
    Messages: 14

    Ok, my email is jnl@copper.net
    The plow worked when I got it, and up to the time we worked on the electrical. That is when the trouble started. The guy who worked on it is a good friend, and reputable. He has been in business for quite a few years. So if there is a problem, I don't believe he did it unknowingly. Then again, mistakes happen.
    The schematic would be great. Just e-mail it.
    PM's??? I use yahoo messenger, but not very often.
    Let me know...
    BigJohn
    jnl@copper.net