D37ex-21a Komatsu electrical problems.

[brandontblevins]

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]

Do you have 24v on 20 pin connector on back of monitor? Pins 1,2 and 5,6.

 

[brandontblevins]

Yes I do. Checked with a multi meter and load tested with a 24volt test light.

 

[coalrulz]

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?

 

[coalrulz]

Change pin 21 from my last post to 22. Wasn't very good at coloring within the lines as a kid.

 

[brandontblevins]

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.

 

[brandontblevins]

Ok. I checked everything. I don’t have any power to anything. Until I turn the switch on then everything does.