# MM Won't angle or drop



## pamante (Jan 20, 2016)

New poster 
Just bought a 1998 Jeep Sahara with an older Fisher MM plow - plow was clearly not maintained well.

I used it once - the next time it snowed the plow wouldn't angle or drop.

Checked and cleaned the connections through the grill

Replaced all the spade connections on the solenoids. The wiring diagram on line is a little different than the Jeep. One of the solenoids looks backwards. 

I can hear the motor run but blade won't move right left or drop

Replaced the fish stick with an aftermarket one.

Big storm coming - help please


----------



## dieselss (Jan 3, 2008)

How many plugs at the grill?


----------



## pamante (Jan 20, 2016)

Thanks for the response

Two plugs at the grill
One for power
The other had lots of pins. There were not the same size pins though. I thought the female part of the connector may have broken off and stayed on the male side - but it doesn't look like it.
Should they all be hte same size


----------



## Randall Ave (Oct 29, 2014)

You did check fluid level? Does the motor sound like it is struggling, or free wheeling?


----------



## dieselss (Jan 3, 2008)

Double check the blk/org at the coils. That's the ground. It comes off the plow motor, that's the small wire off the main ground.


----------



## pamante (Jan 20, 2016)

Thanks for the replies

I actually replaced the ground. It was questionable at best.

It looks like one terminal on every solenoid is connected via black/red wire. I would thing the would all be the same location, back. The S2 ground is on the front terminal. Is that correct?

The motor sounds fine. I can't really tell if there is enough fluid with the lift piston stuck in the up position. From what I can see, it looks foamy like there is air or water in it. Is it just AT fluid?

Paul


----------



## dieselss (Jan 3, 2008)

The 3 coils get there ground from that motor stud up front. Blk/org and are all connected together.
What you could do is run a jumper wire from your trucks ground to the motor just to make sure 
Then your gunna need to see if your getting power to the coils when you operate the controller


----------



## pamante (Jan 20, 2016)

I'll give it a try at lunch

Should I bypass the wiring harness and link the grounds directly to the stud?

Should all the grounds be on the same side of the solenoids? They aren't. Not sure it matters with a solenoid though.

Is the fluid just ATF fluid?

Thanks
Paul


----------



## dieselss (Jan 3, 2008)

Can try going from the motor stud to one of the coils, or straight from your trucks battery.
Atf is ok.


----------



## pamante (Jan 20, 2016)

I checked all the connections I could. I pulled the solenoids and the valve bodies. The S3 (longest) had some bad o-rings. Replaced the whole thing. ($74)

The solenoid on S1 went on hard. The shaft of the valve body seemed swollen at the end. But plow goes up when I push the button - just won't come down or angle.

I drained all the fluid. Very light pink - water and air in it. Could this bad fluid or air in the system be the cause?

It's a yard truck so it isn't registered and can't be driven it to someone to fix it.

Anything I haven't tried?


----------



## dieselss (Jan 3, 2008)

Pink is usually water. Did you also flush out the rams?
If the coil was hard going over the valve, usually indicates a bad valve.


----------



## pamante (Jan 20, 2016)

I drained all the fluid. I'm waiting for a valve cartridge to come in. When I took the coils off the first cartridge it was tight. The cartridge itself looked swollen. Should be here tomorrow. I'll give it a try then.


----------



## pamante (Jan 20, 2016)

OK - I'm at a loss. I replaced all three valve cartridges with aftermarket SAM units. I also replaced the hand held controller unit from SAM as well. I drained the fluid. It was REALLy bad - lots of water. Replaced all the spade connectors. When I try to angle it, it moves slightly then stops. Still won't go down or float. After I replaced the last valve - it angled back and forth ONCE. I'm thinking it could be air bound.


----------



## Randall Ave (Oct 29, 2014)

You cleaned or replaced the filter, and cleaned out the resivior housing? Removed hoses and flushed out the rams


----------



## dieselss (Jan 3, 2008)

While in float, did you test light the coil to see if your getting power to it?


----------



## pamante (Jan 20, 2016)

dieselss;2107593 said:


> While in float, did you test light the coil to see if your getting power to it?


Yes. Driver side coil has power in float
Fault light is intermittent on the controller
Now nothing. No motor spin


----------



## dieselss (Jan 3, 2008)

So you have power at s1/wht/yellow when you go in float and it doesn't lower?

Did you mess with the quill at all?
And you said you inspected the s1 valve itself?
Did you try to hotwire the coil itself, power and ground? Can also try loosening the lift ram nut, might be rusted and putting the lift cylinder in a bind 

Double check where you have the controller powered up at. Wiggle the wire and see if that works.


----------



## dieselss (Jan 3, 2008)

http://library.westernplows.com/doc...level=1&filename=21936_121704.pdf&doctype=pdf


----------



## pamante (Jan 20, 2016)

dieselss;2107619 said:


> So you have power at s1/wht/yellow when you go in float and it doesn't lower?
> 
> Did you mess with the quill at all?
> And you said you inspected the s1 valve itself?
> Did you try to hotwire the coil itself, power and ground?


Correct. S1power and magnetized
What is the quill?
No to the hot wire coil. Will try that now


----------



## dieselss (Jan 3, 2008)

Did you try to add a ground wire directly to the coils bypassing the factory wire


----------



## pamante (Jan 20, 2016)

dieselss;2107626 said:


> Did you try to add a ground wire directly to the coils bypassing the factory wire


Just did. Won't go down. Think it could be air bound?

When I look in the reservoir the ATF looks aerated


----------



## dieselss (Jan 3, 2008)

That's air, but that's not holding you up.
When you replaced all the valves, did the plow then lower when you removed the s1 valve?


----------



## pamante (Jan 20, 2016)

dieselss;2107639 said:


> That's air, but that's not holding you up.
> When you replaced all the valves, did the plow then lower when you removed the s1 valve?


I just took our S1 and the blade goes down
I replaced all the valves


----------



## dieselss (Jan 3, 2008)

Look at page 37 of the mechanics guide I posted for you. Go's through the testing.


----------



## pamante (Jan 20, 2016)

I pulled each of the valves and used a coil I had lying around connected directly to the battery. All three valves moved when I applied power to the coil. I should have used the coil that was mounted on each valve. Now I'll test each coil on one of the valves I have already replaced. I'm thinking about bypassing the harness and hard wiring it. I know I won't be able to remove the plow once I do that - but it would eliminate that connection. The only other thing would be the controller and since it worked once - I'm thinking it is OK


----------



## dieselss (Jan 3, 2008)

"Hard wiring" it was what I was getting at to rule out the controller, and the wiring.


----------



## pamante (Jan 20, 2016)

At my wits end. So far I have;
Replaced the controller $250 with a SAM after market unit
Replaced S1 (short one) shaft had bulged ($38)
Replaced S2 (middle) just because ($75)
Replaced S3 (Long) bad o-rings and damaged plastic ($80)
I also bought a coil - I wanted a known good one for testing.

I drained the fluid from the reservoir and all the rams. With the hoses off I angled the blade left and right to make sure there wasn't anything mechanical binding. Fluid was full of water. Replaced it with ATF. I cleaned both through the grill connectors, power and control.

I replaced just about every spade terminal by soldering them, not just crimping. I replaced the ground wire on the motor and on all the coils. I tried to operate it with a ground directly from under the hood.

I tested each valve by taking it out and putting a coil on it and powering it at the battery. They all moved. Not very much but I could see and hear it. I put all the valves and coils back in and powered them directly from the battery. I could hear them work and they became magnetized.

With everything attached I tried the controller and S1 has power and I can hear it when it is in float mode. But it will not lower.

S2 has power at the valve when angling left and right.
S3 has power at the valve when angling left and on lift.

The motor spins whenever I push a control button. It tries to angle when I push the angle buttons but it seems like something is stuck. It won't go down or float. If I remove the valves or any line it seems to work once, left and right. But then that's it. 

I'm ten minutes away from selling the whole thing as scrap. Any assistance would be appreciated.


----------

