M1031 pto dash light

[sebaeb]

I checked continuity on the switch...it seemed ok the first check but then checked it again and now nothing....i pulled the mag switch and this is what the tip looks like...is it suppose to be flush or is the probe suppose to stick out alittle bit from the end?

 

[Keith_J]

That which you pulled is the speed sensor, it senses every time a gear tooth passes by as it is a Hall Effect Sensor. Yes. there is a magnet in it, the gear tooth changes the magnetic field and it senses it. Counting the impulses over time is how the governor determines speed. It has nothing to do with the governor light. Now you will have to reinstall the speed sensor and it can be quite delicate to install. Too far and it will break, too shallow and it won't sense speed.

The switch you need to check has a single wire going to it. It grounds when the PTO is engaged.

You need to check out the transfer case and transmission interlock switches. The transfer case is linked to the shifter rod in the floor, remove the bezel and trim around the transfer case shifter rod, just a bunch of Phillips screws. Or you can go underneath.

The transmission interlock switch is under the hood near the steering column where the shifter rod connects to the transmission.

You need to follow the wiring diagram I have posted carefully. The PTO light should only be on when the transfer case is in neutral, the transmission in drive and the PTO pulled.

 

[sebaeb]

I didnt move the jam nut when i removed the speed sensor...i re-installed it , i removed the indicator switch which has the ball on the end..i looked in the hole and saw the finger which would have contacted the ball end of switch, plus the blue pto knob was pushed in(off position)..light off normally...but pull blue knob and finger moves away from ball end light on then?....im thinking maybe someone has the cable arm mounted on wrong...when blue knob is pushed in ...pto normally off... but my light stays on...pull blue knob out my light goes out..?

 

[sebaeb]

Pulled PTO indicator switch..continuity checked good...will trace wire from switch to cab and check for any damage

 

[bshupe]

I love threads like this. Not because a guy is having trouble but because of all the help he gets when he takes the time to write a sensible question, reply promptly and with photos etc.

Good work gents.

 

[sebaeb]

Can anyone with a m1031 with working generator crawl underneath their truck and check to see if the pto indicator switch is the same color as mine?....i ask because there are two different switches that could be used...normally open or normally closed...not sure which one i have but this one is white...muncie says the other is black...maybe the army tried changing mine out and installed wrong switch....thanks in advance!

 

[sebaeb]

P.S....it is located on the PTO unit one wire going to it....just need to gently pop the cap off and you should be able to tell the color of switch

thanks steve

 

[dependable]

The one I have is whitish, but has a spade connector instead of the pin on yours. It also looks like it was recently replaced. Both the ones I bought (sold one to a friend) in 2010 had had repairs to PTO unit, with some new parts and lots of RTV blue.

 

[Keith_J]

Can anyone with a m1031 with working generator crawl underneath their truck and check to see if the pto indicator switch is the same color as mine?....i ask because there are two different switches that could be used...normally open or normally closed...not sure which one i have but this one is white...muncie says the other is black...maybe the army tried changing mine out and installed wrong switch....thanks in advance!

My PTO system works perfectly, the switch on the PTO has the black insulator.

There might be something else wrong with the governor which is why they kludged the throttle cable and swapped the switch.

 

[sebaeb]

I know the PTO on our M1031's are a model TG series...but does anyone know the model number?...are they all the same models on the M1031's?...according to muncie they think i have a 1&4 assembly...which means the belly of the PTO is high and the center line of the rear output shaft is at or above centerline thus should have the white normally open indicator switch...but keith_j has the black switch...???

 

[Keith_J]

Per the -23P TM, part number is TG6S-N7018-C2BT. The switch is part number 30M13004

Realize the TMs weren't published until 1992 for the -23, 1994 for the -13.

What I think happened with your vehicle is modifications to make it work because the TMs were not available. There were a few times when we had such issues with civilian equipment pressed into military service that had to go back to the manufacturer for service.

I doubt the technical design package was released before the technical manuals.

 

[dependable]

As per the diagram Keith J posted in post 10, the PTO indicator switch is closed to ground. Should be pretty easy to test that. (If you ground the switch terminal , the light should be on)

 

[sebaeb]

Have some free time this afternoon to trace some wires , but have some questions...in the post #10 that keith_j posted where is the relay located that is pictured in the lower left?...it has wires from the drive switch indicator and transfer case neutral switch going to it?...next question...the white wires coming from the gov actuator one of them has a bulb looking fuse holder thing inline with it...i have included a picture...what is it?...i pulled it apart...nothing in it but a pin prong connection? or something of the sort?...plus the drive indicatoe switch has a cover...mine was hanging by one screw...i noticed the back side of the switch has a roller and moves in and out...is it supposed to contact the cover when the cover is bolted in place?

thanks steve

 

[lavarok]

All the relays are in the rear compartment under the cover you removed, along with the over speed control, the governor, and the ramp generator. That is not a bulb holder, its a plug to fill the unused connection. As for safety switches, my current truck has them all removed and bypassed so dont have anything to visually inspect to verify at this time.

 

[sebaeb]

Well so much for getting much done today...got called to work, thats what ya get for working for the Railroad, but anyways yes i found the relay i was asking about...i think my transfer case neutral switch is out of adjustment...took a picture of it when my TC is in "neutral" position ...correct me if im wrong but the lever should be contacting the spring coil of the switch?

thanks steve

 

[dependable]

Here are pictures of drive switch installed.

Have no idea what that 'fuse holder thing' is by your governor, I don't think it is stock.

 

[Keith_J]

Well so much for getting much done today...got called to work, thats what ya get for working for the Railroad, but anyways yes i found the relay i was asking about...i think my transfer case neutral switch is out of adjustment...took a picture of it when my TC is in "neutral" position ...correct me if im wrong but the lever should be contacting the spring coil of the switch?

thanks steve

The lever arm on that switch is seriously bent out of shape. As we would call it, ATFU.

You might be able to fix it but being spring steel, it looks intentional. I dread what you are going through will be a long road to functionality. Keep up the effort, we will help you. I can go take pictures of mine, that should do you some good.

Ok, these should do you. Note the sensitive switch insulator is black.

 

[lavarok]

You can always bypass the safety switches. Just make sure you install a master toggle switch (or two) in the circuit somewhere to prevent inadvertent use by unknowing and/or unauthorized drivers. Right now I have one in my cab and plan to install a second master toggle in the rear box to prevent any mistakes. I also keep a laminated step by step guide on using the system in my truck to make sure I dont screw up.

At least if you bypass the switches you can move on to testing the other components.

 

[sebaeb]

First off i must say thank you guys for the knowledge and pictures you have provided...its been very helpful to say the least. Keith_j...the picture you posted of your TC neutral switch...what position was it in?...id guess 2H?...I havent checked yet but is there a parts store or other vendor that sells this TC neutral safety switch?

thanks steve

 

[Keith_J]

Yes, the transfer case was in 2H for the picture.

The switch is a Honeywell BZ2RW8299A2.