2000 Komatsu PC200-6 Dead short

[Dirtyboy1]

Hello everyone. I am wondering if anyone might be able to help me. I have a 2000 PC200-6.
Fuse number 5 has a dead short (short to ground).

I grabbed my manual, fuse 5 powers radio, heater , cigarette lighter, left hand knob and windshield wiper pump and a/c.

I looked at the schematic (Komatsu schematics a bit to be desired ).

So here is what I did. I unplugged the windshield wiper pump, heater controls, the machine has no a/c on it. Stereo, heater fan box. Still dead short.
Looked at circuit schematic again thinking I missed something. I didn't disconnect the left hand safety control knob as it works.

Did a visual inspection and didn't see any chafe d wires. She is a good old machine, would really like to fix her. Thanks in advance for any help.

 

[AllDodge]

Shorts are just hard to find and only way to find is physically trace wires

Remove the fuse block and look under it
The machine doesn't have AC but the wires are still there. Look where they would be if it was installed.
Feel along the harness on the motor to see if it has rub thru the insutaltion

 

[HarleyHappy]

Check that your cirgarette lighter isn’t stuck in.

 

[Simon C]

Good if you have a mini clamp meter to check the wires for actual load. Each plug in that has a pin connection that is partially loose will cause more heat a help blow a fuse. If you have disconnected everything on this machine connected to Fuse 5 you have a harness grounding out somewhere. Pull the fuse out and see which pin is the battery power. Disconnect your batteries.
Take a 60 watt bulb and hook it to your battery posiive from a 10 Amp ATO fuse holder and hook the ground end of the 60 watt light to the fuse panel cold side of the #5 fuse pin receptacle. If every thing else is disconnected according to schematic nothing will light. If it does light , Go down stream of the fuse panel and disconnect one plug at a time. If you disconnect at the first plug Connector CNH12 and the light is still on the harness is shorted inside to ground somehow. You will have to go down stream of the power source one plug at a time , to find where it is.
If you don't like Komatsu's schematic which I have, wait till you work on a Case or some new stuff.
You will have to check about 10 plug ins but will find it this way. When you get down to connector CNH12 unplug it and the 63 pin large connector at the same time. These are 2 different ways on the schematic. If you disconnect both at the same time you will know when you reconnect which side is grounding you out.
Simon C

 

[Coaldust]

Check that your cirgarette lighter isn’t stuck in.

Or, guys accidentally drop stuff into the socket. Loose change or screws that short it out.

 

[maps67]

I had a similar issue on my PC200-6, in my case it turned out to be a pinched wire behind the seat going to the heater circuit. I’d check the harness around the cab corners, those spots seem to rub through over time.

Mini Militia App Lock​