Dukw

HELP! M-915 AM General, Put in drive, Engine dies? What the #%&* ???

I have a 1984 AM general tractor with Cummins engine, Ran great the day before and it shifts fine, good batteries.
This morning go to move it and turn key to “ON”, push the start button…nothing.
Checked the starter by the old farmer method… placing ¾ inch wrench on HOT battery terminal and jump over to positive terminal on solenoid and starts and runs fine.
Problem #1
No power to solenoid when dash button is pushed.
Problem#2
When engine is running and air is at the operational level of pressure, I go to place in gear and engine dies???
I believe this problem is a safety switch or some kind if idiot override. And I’m the Idiot.

Thanks for the help!

Rob

cornrichard

I don't know what is causing your problem but I have something you can check. Look on the drivers side of the engine. Find the pt pump. Your throttle linkage is hooked to it. On top of the pump is an electric solenoid that shuts of the engine when the key is turned off. There is a hand turnable screw on the side of the valve facing the radiator. If you turn this screw the valve is manually held open. If your truck stays running after that then you have an electrical problem or a bad solenoid valve.

porkysplace

The black type is really hard to read.

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Technical Manuals

cornrichard

Oh yeah, you can get a copy of the TM at this link. Free Military Army Manuals! Then you can save yourself a ton of wasted replies telling you to read the TM's. You will take joy and fun away from about a third of the posting members here if you can say you have done your homework.

wreckerman893

Do you have the key in the "ON" position when you jump it across the soleniod?

I have jumped the M915/916's across the seleniod inside the dash panel when there was no key with the truck. You may have an ignition switch problem.

If you don't have the switch "on" the truck will run but you will have no lights or instruments. That may be denying power to the fuel shutoff switch.

I have not had one shut off when I put it in gear after jumping across the seleniod......electrical gremlns are the worse.

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Fixlinc

Would make sure the key switch is good first. There is also a neutral safety switch on the trans in the circuit but it is only so it doesn't start if left in gear but could be a short down there or bad switch with back feeding causing other problems too.

Floridianson

I have the cat service manual at the motor pool and willl look at it. Seems more like you front clutches are not fully disengaging at idle.

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James
1 Bobbed 5 ton with lockers in rear and W/W
30 Outher Military Trucks
4 Military Cranes
3 Military semitrailers
2 Military expandable semitrailers
3 military gens. 3k 5k 10k
And storage of to many Military parts that it might be a sin.

fasttruck

If the chassis was manufactured in 1984 it should be a 915A1 with an allison 5 speed auto trans. . .