This fault occurred straight after a heavy rain. I found that the engine ecu fuse was blown, changed it out and it blows again when unisolated. Noticed wiring harness plug out back of the cab had the top layer wires with isolation missing exposing wires, that were still wet from the previous nights rain. I dried and repaired the wiring that had been exposed to the weather I’m guessing was the fault of the dead short. The fault still remains, I than unplugged the engine ecu and the fuse doesn’t blow. I’m thinking the wiring loom is okay, only shorted from the wet exposed wiring. And the ecu has been fried in the process, any thoughts?
Welcome to HEF Chris ! CAT guys will require a serial number.
Thanks for having me I will be able to supply serial when I’m at the machine again, in the morning.
Start with a Serial Number please, so we can look at the electrical schematic. There must be 50 different models of 972. At first blush a short in a wiring harness should not blow an ECM (that's why they have fuses) but stranger things have happened. I sould suspect there is another short somewhere.
Here is the Serial if you want to check the schematic 972HLAG02188
I think you are missing a character between the "972" and the "02188". There should be 5, you only have 4.
972HLA7G02188 that one should work a bit better
Check your messages. I sent you an electrical schematic. First question is exactly which ECM fuse is blowing.? There are 3 x 15A unswitched power ECM fuses - #22, 23, & 24, and 1 x 10A switched power fuse #8
Fuse 22 is the culprit here
Try unplugging the 70pin connector for the Engine ECM at the engine end. Does the fuse still blow.?