PTO winch help

[CONJIN]

Trying to get the PTO winch going on my new to me 1998 M1078. Everything on the truck works except the PTO winch. I was able to hot wire the PTO by jumping pin 30 to pin 87 on the K37 PTO relay socket and the instrument light came on and the PTO was engaged and running. Following the wiring out on sheet 12 of the wiring diagram, I find relay K42-87 ENG PTO. The drawing shows it in the power distribution panel, PDP. It does not exist there on my truck, there is literally no socket marked K42 or ENG PTO. Does anyone have any insight on this? I've literally hit a brick wall.

 

[Ronmar]

Well that doesn’t look like an A0 schematic. The K37 and the year indicate to me that you have an A0 with a wtec 3 transmission controller, so I don’t think you have a K42…

The PTO sw has 2 switched contacts in it. One sends power to-from that relay And the PTO engage solenoid. The other contact sends one trans controller output signal out thru that switch and back to two pins on the transmission connector. I believe one of those pins activates the WTEC PTO programming, and the other provides the feed power that the controller then loops back out to energize K37 and actually engage the PTO If all the requirements for PTO mode are satisfied(truck in neutral and engine below a certain RPM I think)…

here is a screenshot from the schematic I think you should be using. It is in the back of every A0 manual, but if you message me your email I will send you a standalone .PDF file with just this schematic on it(34 pages)…

 

[CONJIN]

Well that doesn’t look like an A0 schematic. The K37 and the year indicate to me that you have an A0 with a wtec 3 transmission controller, so I don’t think you have a K42…

The PTO sw has 2 switched contacts in it. One sends power to-from that relay And the PTO engage solenoid. The other contact sends one trans controller output signal out thru that switch and back to two pins on the transmission connector. I believe one of those pins activates the WTEC PTO programming, and the other provides the feed power that the controller then loops back out to energize K37 and actually engage the PTO If all the requirements for PTO mode are satisfied(truck in neutral and engine below a certain RPM I think)…

here is a screenshot from the schematic I think you should be using. It is in the back of every A0 manual, but if you message me your email I will send you a standalone .PDF file with just this schematic on it(34 pages)…

View attachment 871447

Well having the right diagram would certainly help! I got mine off the Midwest Military Equipment website and it was the only one on there, didn't occur to me that there could be others! Thanks for the info! Hopefully I can find the problem.

 

[CONJIN]

Well that doesn’t look like an A0 schematic. The K37 and the year indicate to me that you have an A0 with a wtec 3 transmission controller, so I don’t think you have a K42…

The PTO sw has 2 switched contacts in it. One sends power to-from that relay And the PTO engage solenoid. The other contact sends one trans controller output signal out thru that switch and back to two pins on the transmission connector. I believe one of those pins activates the WTEC PTO programming, and the other provides the feed power that the controller then loops back out to energize K37 and actually engage the PTO If all the requirements for PTO mode are satisfied(truck in neutral and engine below a certain RPM I think)…

here is a screenshot from the schematic I think you should be using. It is in the back of every A0 manual, but if you message me your email I will send you a standalone .PDF file with just this schematic on it(34 pages)…

View attachment 871447

I've got the winch working just by removing the PTO relay and jumping pin 30 to pin 87. Basically bypassing all the transmission and rpm sensor stuff. Yes, it's looking for neutral and rpm between about 1200 and 1500. The winch switch gets power from the PTO switch and then sends it to the winch in/out switch. The weird thing is that I get the PTO engaged symbol on the instrument panel, but the winch symbols don't light up even though they are powered by the respective switches, but at least it's working and I would rather have the choice to be able to drive and winch at the same time for better self recovery

 

[Ronmar]

Did this truck have a winch originally, or was it a retrofit?

 

[CONJIN]

Did this truck have a winch originally, or was it a retrofit?

It's original to the truck. Truck only has 1500 miles on it. When I hit the lamp test switch only a few indicator lamps light. I'm assuming they should all light. Like I said, the PTO indicator lights now, but it doesn't with the test switch. Same with the fan switch. Doesn't test, but comes on with the fan switch (although the fan solenoid doesn't seem to work, fan continues to run). Gremlins in there somewhere.

 

[coachgeo]

It's original to the truck. Truck only has 1500 miles on it. When I hit the lamp test switch only a few indicator lamps light. I'm assuming they should all light. Like I said, the PTO indicator lights now, but it doesn't with the test switch. Same with the fan switch. Doesn't test, but comes on with the fan switch (although the fan solenoid doesn't seem to work, fan continues to run). Gremlins in there somewhere.

sounds like some power source is shorted to ground.

 

[CONJIN]

sounds like some power source is shorted to ground.

Possible, but I've got bigger problems now. Took it down to the gas station, first trip since being delivered. Gas station is about a mile away. Got there fine. Went to leave and it wouldn't shift into gear, 7 just flashing. Found trans to be super hot. Trans seems to be full on dipstick, but hard to tell, definitely fluid in there though. Cooled it off with a water hose and letting it sit for awhile. I was then able to drive it back home .
Trans oil temp light never came on, but it is one of the few that does come on when I do lamp test 2nd picture. 1st picture is main power on and eng off. Just the yellow lights are visible, the red are only visible on the camera.

 

[Awesomeness]

Possible, but I've got bigger problems now. Took it down to the gas station, first trip since being delivered. Gas station is about a mile away. Got there fine. Went to leave and it wouldn't shift into gear, 7 just flashing. Found trans to be super hot. Trans seems to be full on dipstick, but hard to tell, definitely fluid in there though. Cooled it off with a water hose and letting it sit for awhile. I was then able to drive it back home .
Trans oil temp light never came on, but it is one of the few that does come on when I do lamp test 2nd picture. 1st picture is main power on and eng off. Just the yellow lights are visible, the red are only visible on the camera. View attachment 871610View attachment 871611

The transmission is "cooled" by a heat exchanger below the radiator, using engine coolant. So it's normal operating temperature is the engine's temperature... 200F+. The temp may not be a symptom of anything.

Even though you only drove a mile, it typically only takes my truck a few miles to get warmed up (except in winter/freezing temperatures). So I would expect it all to be too hot to touch, even after a short drive. It's a good idea to keep an IR non-contact thermometer gun in the truck, and use it to start getting a feel for what is normal temperature for things (e.g. axle hubs, axle differentials, tire sidewalls, etc.).

On another note, it's pretty crazy to think about how much energy liquid fossil fuels contain, and how inefficient internal combustion engines actually are (~20%). In a mile of driving, you probably burned a bit less than a quart of fuel, and heated a combined ~3000lb of metal (engine + transmission) and fluids by about 100F.

 

[Ronmar]

The A0 lamp test is an inside joke Welcome to the party pal… it is only wired to light 2 lights in the annunciator panel…

The TPS on top of the engine has a large effect on shifting…

 

[Ronmar]

It's original to the truck. Truck only has 1500 miles on it. When I hit the lamp test switch only a few indicator lamps light. I'm assuming they should all light. Like I said, the PTO indicator lights now, but it doesn't with the test switch. Same with the fan switch. Doesn't test, but comes on with the fan switch (although the fan solenoid doesn't seem to work, fan continues to run). Gremlins in there somewhere.

The fan is reverse logic, the thermal sw or the dash sw applies power to energize the fan solenoid and provide air to release the fan clutch(cold engine or fording high water). When you hit 205F, the thermal sw opens the circuit, the solenoid de-energizes venting clutch air and causing it to fully engage. Does the fan solenoid release and vent air when you turn off the main switch? With the main sw off, you can reach in under the front and sides and the fan should be locked solid in place. With air tanks full, and engine off, if you turn on the main sw you should be able to reach in and rotate the fan(solenoid on, air applied, clutch released).

This is a good test to run from time to time to see that the fan clutch is locked up solid and the fan rubber bushing(old style fan) is still solidly holding the fan. And with the clutch released, how much play is in the bearings and how smoothly the fan rotates/freewheels…

 

[CONJIN]

The fan is reverse logic, the thermal sw or the dash sw applies power to energize the fan solenoid and provide air to release the fan clutch(cold engine or fording high water). When you hit 205F, the thermal sw opens the circuit, the solenoid de-energizes venting clutch air and causing it to fully engage. Does the fan solenoid release and vent air when you turn off the main switch? With the main sw off, you can reach in under the front and sides and the fan should be locked solid in place. With air tanks full, and engine off, if you turn on the main sw you should be able to reach in and rotate the fan(solenoid on, air applied, clutch released).

This is a good test to run from time to time to see that the fan clutch is locked up solid and the fan rubber bushing(old style fan) is still solidly holding the fan. And with the clutch released, how much play is in the bearings and how smoothly the fan rotates/freewheels…

The fan is always up, it's never freewheeling. Which is of course better. Something else to look at

 

[CONJIN]

The A0 lamp test is an inside joke Welcome to the party pal… it is only wired to light 2 lights in the annunciator panel…

The TPS on top of the engine has a large effect on shifting…

Good to know! I'm an aircraft tech for United. When I go in the cockpit and hit light test, it lights up like a Christmas

 

[CONJIN]

The transmission is "cooled" by a heat exchanger below the radiator, using engine coolant. So it's normal operating temperature is the engine's temperature... 200F+. The temp may not be a symptom of anything.

Even though you only drove a mile, it typically only takes my truck a few miles to get warmed up (except in winter/freezing temperatures). So I would expect it all to be too hot to touch, even after a short drive. It's a good idea to keep an IR non-contact thermometer gun in the truck, and use it to start getting a feel for what is normal temperature for things (e.g. axle hubs, axle differentials, tire sidewalls, etc.).

On another note, it's pretty crazy to think about how much energy liquid fossil fuels contain, and how inefficient internal combustion engines actually are (~20%). In a mile of driving, you probably burned a bit less than a quart of fuel, and heated a combined ~3000lb of metal (engine + transmission) and fluids by about 100F.

The problem is I only went a mile and after shifting to neutral it won't go back to drive till it cools off. When I got back home I switched to neutral at the top of the drive, see if it will roll in neutral and it doesn't. It's like I set the brake. Also can't shift back into drive until it cools again. One mistake I made was to check the trans fluid with the engine off. I'll have to check it again. Not rolling in neutral is really bothering me.

 

[Ronmar]

Are you sure your brakes are all unlocking?

 

[CONJIN]

Are you sure your brakes are all unlocking?

Well now that I think about it, there was a caging bolt in one of the air chambers of the right rear brake, but it wasn't tight, just laying there and I took it out and promptly forgot about it . Thanks, definitely something to check

 

[Ronmar]

These trucks went to DRMO for a reason…

 

[CONJIN]

Are you sure your brakes are all unlocking?

Are you sure your brakes are all unlocking?

These trucks went to DRMO for a reason…

I suppose, but this truck is decievingly clean. No oil leaks anywhere. The only air leak I found is all 3 lines going into the cab leveling valve. Took the lines out of the quick release fittings and put them back in with some silicone around the edge and now it works great. Cab doesn’t sink down for a long time after shutdown now.
I also put the caging bolt back in and now it rolls, but of course now I have to figure out why it's not releasing. Don't hear any air leaks.

b7dfb20e168d7abe45d84053ab01c406411800e7.1

 

[Ronmar]

I suppose, but this truck is decievingly clean. No oil leaks anywhere. The only air leak I found is all 3 lines going into the cab leveling valve. Took the lines out of the quick release fittings and put them back in with some silicone around the edge and now it works great. Cab doesn’t sink down for a long time after shutdown now.
I also put the caging bolt back in and now it rolls, but of course now I have to figure out why it's not releasing. Don't hear any air leaks.

b7dfb20e168d7abe45d84053ab01c406411800e7.1

I did a youtube vid on how the rear brake components function, under username rronmar

 

[CONJIN]

I did a youtube vid on how the rear brake components function, under username rronmar

Thanks, I'll check it out. All help is greatly appreciated! As far as the trans, I got the truck as level as possible and it's showing at the low end which is probably like 10 quarts low on these! Guessing that's the problem, but I'm going away on vacarion for the next 2 1/2 weeks, so it will have to wait. I read some posts about switching to ATF instead of the hydro. This might be a good time to switch over, the shifts are ridiculously harsh!