John Deere 350 bulldozer sudden shut down

[mleonard53212]

I have a 1969 dozer with a M43TF type diesel engine. This vehicle will shut itself off randomly. And not just the engine, the lights will also shut off.

Several times, I will fire up the machine and allow to idle. I will turn on the headlights as well. The machine will idle fine, with no indication of an issue. Suddenly, it will simply shut itself off--the engine and the lights. This will happen at 2 minutes, 7 minutes...no specific time frame. Once it self shuts off, it will take many minutes for the issue to self correct. The lights will come back on, and I am able to fire up the machine. However, it will shut itself off randomly.

When the engine is running, I will shake and manipulate the main wiring harness to try and get a reaction but nothing. I did have an issue with the 'kill wire' to the fuel solenoid, however when this wire gave me problems, the lights did not die, only the engine and after replacing the wire, the engine fired right back up.

When the machine self-kills, there is power from the battery to the starter motor, but pressing the start button on the dash does nothing.

Basically, the machine shuts itself off mechanically and electrically, then will self fix the problem and allow to run some time later. However, it just shuts itself off once more. It is almost like something is heating up and causing the failure, then when it has time to cool down, will return to normal.

Any assistance will be greatly appreciated.

[Jim B]

Welcome to the Boards.

This sounds like the 20-amp circuit breaker (JD # AR28403) is opening due to excess draw through it or it is getting weak. I am not sure just where it is but think it is behind the dash panel. This means you may have a wire shorting to ground causing it, or the fuel solenoid is drawing too much, unless the breaker is just weak.

You can find the breaker and test the two terminals on it when the crawler dies to see if both terminals are live, it will tell you if the breaker tripped out. only one terminal live right after it dies indicates the breaker opened. You need to check quickly as those breakers reset themselves after they cool. If one terminal was dead, try replacing it (your local auto parts store or JD dealer should have something for a 20-amp breaker that has similar terminals and mounting. If that cures the issue, it indicates a weak breaker. If it still drops out, you likely have a high draw somewhere to find.

Your post about your 350 should be made on the Late Models Board. A moderator will likely move it when they see it here, so don't be surprised to find it over there.

Good luck.

Jim

[mleonard53212]

Solid info Jim. Thanks.

[Jason37756]

Run a wire directly from the injection pump to the battery. There should be some type of wire(s) already connected to the injection pump, unhook those and ensure you have a single wire to the positive battery stud. This method bypasses the key switch or button…or both in terms of the pump being ready to deliver fuel. Being a ‘69 she’s probably a worker not a looker, so a little wire bypass is usually in order.

After getting the dozer started unhook the positive battery cable from the battery ensuring your injection pump wire is still connected to the battery…helps to have three hands. You won’t have any other electrical functions…lights, switches, alternator…you’ll simply pull the wire off the battery to kill the engine.

Jim has given you good advice in looking for the tripped breaker or something pulling amps. Seems as if something is heating up, causing the trip, and thus the injection pump shuts off. The lights are a result of the same problem.

Just my 2 cents. I’ve started many old pieces of equipment without the first thought of what else could be going on with the wiring, switches, gauges, alternators, missing keys, etc. These things could take hours to diagnose. Divide and concur…get it loaded or in the dry then find and fix the problems.

[mleonard53212]

Thanks. Will give it a shot.