Cat 966C Electrical Problem - Need help to diagnose cause

[swampdog]

This is on my Cat 966C loader. It runs well but recently most of the electric accessories don't work. All the switches in the control panel located on the upper right pillar in the cab don't work.

A test light shows that power is not going to any of the switches there - that includes the wipers, defrost fan, heater fan, and exterior lights. All the fuses in the control panel where the switches are located look good.

I've looked for a broken wire or a master fuse or something like that. But the wiring is difficult to trace on this machine.

Where should I start to look for the cause of the problem? Can anyone point me in the right direction? Thanks.

 

[Lee-online]

Do you know how to read a schematic? That way you can trace it out to see where the power is being lost. With a serial prefix i can get you a schematic.

It could be a relay, circuit breaker, bad connector, chaffed harness.

 

[grandpa]

Power for that panel comes from under the dash and go down over to the post and then up to that panel. Your gonna have to take the knob off the air brake valve and then the big nut off the valve to get enough slack to lift the dash panel up high enough to service under there..... good luck ..
Gramps

 

[swampdog]

Do you know how to read a schematic? That way you can trace it out to see where the power is being lost. With a serial prefix i can get you a schematic.

It could be a relay, circuit breaker, bad connector, chaffed harness.

Thanks to both of you who replied and the ideas.

I would like to have the schematic - my manuals don't include a schematic of that part of the electrical system. The Serial No. prefix is 30K (about a 1979 build).

 

[grandpa]

Thanks to both of you who replied and the ideas.

I would like to have the schematic - my manuals don't include a schematic of that part of the electrical system. The Serial No. prefix is 30K (about a 1979 build).

30k is canadian built.... I have one, pretty straight up... you can fix it.

 

[truecountry]

My first thing is look for big wads of black tape ups and start there and tag alongs the blue plastic clips to add a wire they corrode quick ...if you didnt find anything there look for places where wires are bent to run inside of metal ...Good luck

 

[Lee-online]

Ah, sorry that is a little too old. Cat didn't scan all the older stuff so they aren't online, It would be on the microfiche and that is at work. They are very basic schematics anyways because it is basic wiring. A little probing and you should be able to find the problem.

 

[Bluox]

Thanks to both of you who replied and the ideas.

I would like to have the schematic - my manuals don't include a schematic of that part of the electrical system. The Serial No. prefix is 30K (about a 1979 build).

Swampdog,
If you have a parts book look under cab section,it shows the cab wiring harness. power goes to panel in a white 10 gauge wire.
good luck
Bob

 

[swampdog]

Thanks everyone for your help. Problem fixed! The red wire that feeds the control panel on the upper pillar was disconnected from the bigger wire under the dash panel.

 

[grandpa]

your welcome swampdog.... did you have to take the park valve loose to get in there?

 

[swampdog]

grandpa - No, I lay on my back across the seat, and managed to stick my head and hands under there far enough to do the job.

 

[grandpa]

grandpa - No, I lay on my back across the seat, and managed to stick my head and hands under there far enough to do the job.

lol... good for you,,, tell's me your alot younger than me!!!