M929 Won’t Start

[tmuenster]

My M929A1 Dump Truck won’t start. I bought the truck from Memphis Equipment and they did a 12v conversion on the truck, which in hindsight might have been a mistake.

I got out my volt meter and checked the battery first. The battery is at 12.5v which might be a little low but the truck has been sitting awhile. I did try to jump the truck and no luck there starting.

Next, I moved on to the solenoid for the starter. If I am not mistaken, I think there should be 12v at all three terminals when the ignition key is turned. Is that correct? I had 12v at one terminal but there was 0.0v at the other terminals whether the key was turned or not. Please let me know if you think the solenoid is bad and should be replaced.

Thanks,
Tom

 

[Mullaney]

My M929A1 Dump Truck won’t start. I bought the truck from Memphis Equipment and they did a 12v conversion on the truck, which in hindsight might have been a mistake.

I got out my volt meter and checked the battery first. The battery is at 12.5v which might be a little low but the truck has been sitting awhile. I did try to jump the truck and no luck there starting.

Next, I moved on to the solenoid for the starter. If I am not mistaken, I think there should be 12v at all three terminals when the ignition key is turned. Is that correct? I had 12v at one terminal but there was 0.0v at the other terminals whether the key was turned or not. Please let me know if you think the solenoid is bad and should be replaced.

Thanks,
Tom

View attachment 928471

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Well... Yeah, if you had known that it was 12v vs 24v you might have acted differently.

The best part is that the solenoid is a cheap fix.
You might find a bad switch.
Is it a key type switch?
They cause a lot of problems..

 

[Valley Rock]

The center wire is your activation wire for the solenoid, it tells the solenoid to do its thing and send juice to the starter .

When you turn the key or starter switch all the way to the start position, that wire should be hot, activating the wire on the right .

 

[juanprado]

A a quick test is to jump the solenoid with a screwdriver to complete circuit

 

[fuzzytoaster]

You should contact Doug at Memphis Equipment since he was your POC for the truck and the modifications. We here are just shooting in the dark based on basic operations of the solenoid. Who knows what they did to convert it.. . If anything you can screw in the fuel shutoff solenoid and jump it directly at the starter. If that doesn't spin the engine (at the very least) then you have battery or battery connection issues.

 

[tmuenster]

Thanks for all the help and suggestions. I did call Memphis Equipment this morning. They advised to check the fuses for the ignition. They are the old style glass fuses, which do appear to be fine. However, they said to check with a test light as the fuse holders can sometimes not make good contact.

The truck has been frustrating. I thought it would be less of a maintenance headache having been through the reconditioning process at Memphis Equipment. In the end, all equipment especially military vehicles will need some maintenance I guess.