Hi, I have a Caterpillar 320c that the wiring harness, near the valve block and hydraulic pump is melting, the plastic that evolves the wire is somehow rot, never seen anything like that, I already isolated those damagem wires. First I was thinking about the cleaner liquid we used, but we used it in other machines (not Cat) with no problems. Anyone with similar problems? Old cats used to have better wiring. Thanks
can you post a picture of the harness? what type of cleaner are you using?
Is the insulation swelling, softening and falling apart? I can't remember where I've seen that, not on a Cat. I assumed it was caused by oil or fuel, but can't prove it or really offer any evidence even. Another factor may be heat, the old wiring didn't have much demand on it (amps) and was sized bigger for the load because the insulation was more primitive.
I find a lot of our older equipment that has wiring problems is due to a mixture of heat and being soaked with oil from blown hoses repeatedly. By wiring problems I mean insulation falling off and or becoming spongy and porous. Then causing corrosion and breakage to the actual wire.
Sounds like something that has come in contact with the plastic has caused the problem causing break-down of the material Fuel,Oil,cleaner, could be any 1 of these or if the harness is exposed to light then UV rays could be the problem. Plastic,vinyl chloride ,a man made molecule, is not forever.
Are you sure the problem is not being caused by excessive heat in the engine compartment..? Its not unknown for these machines to have exhaust leaks.
A dirty connector will cause resistance and heat, another possible cause
It is happening only on the wires that took an oil bath... The machine is currently working in Africa with 10.000h on it, altough we take a good care of her, the work she is doing its like being on vacations, soft soil, loading 8 to 10 trucks per day, it looks like a new machine, We have a 330C with the same problem in some wires. We isolated those wires with tape. Our older 325 (Aseries) has the wiring like new, with 13.000h ont the clock. I am losing the ideia that that having a Cat is different from having other brand like Komatsu or Hitachi.
Can you post a photo of the damage ..?
Its been my experience that cat wiring harneses can't stand up to too many oil baths. We've had to replace several harnesses on some of our equipment (385c, 988g) due to the wire coating disintigrating after a couple of good baths from hydraulic/hose issues. Even grease left on the wires will decompose the rubber skin.