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D37ex-21a Komatsu electrical problems.

brandontblevins

New Member
Joined
Apr 3, 2024
Messages
4
Location
Kentucky
Hi I’ve got a d37ex-21a komatsu dozer. In the shop. It came in with a complaint of one track that wouldn’t pull. But it also has a communication error. Dafrkr. E03. The dozer will start and run. Also the blade with function. But no tram. What so ever. It’s had a complete wiring harness put on it. New hst controller. The correct part number. Also it has a new instrument cluster. I have checked all the powers and grounds. The wiring all seems good. I also check the two 120 ohm. Resisters that are behind the dash and the seat. I’m really scratching my head with this one. And nothing on the gauge cluster works. But just as soon as you turn the key. In about 10 secs it pops up that code. Also the hst controller has a green light in the sight glass. Has anyone encounter this? Any suggestions would be appreciated. I’m really scratching my head with this one.
 

coalrulz

Senior Member
Joined
May 10, 2009
Messages
251
Location
Western US
On CN-ST3 40 pin connector at HST controller do you have 24v at pins 1, 2, 11, 12, and 21?
With key on should also have 24v at pins 24 and 14?

1713915436262.png
 

brandontblevins

New Member
Joined
Apr 3, 2024
Messages
4
Location
Kentucky
I’d heard that. lol. Sorry for the later reply. I’m out of town. And I’ve having some internet issues. I did check all of those with a multimeter. But I didn’t load test them with a test light. I’ll have to double check that this weekend when I get back in town.
 
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