I HAD A WIRING FIRE IN MY 1996 KENWORTH W900L SEMI-TRUCK,IT STARTED IN 1 OF THE BATTERIES AND SPREAD TO THE STARTER AND INTO THE SLEEPER POD.IT HAS 3x12volt BATTERIES ON IT,24volt STARTER MOTOR AND THE REST IS A 12volt SYSTEM.I AM IN DESPERATE NEED OF A WIRING DIAGRAM FOR IT. CAN ANYONE HELP ME PLEASE KEITH UK

check wires and connections for damage or frayed --test battery [load test] and starter

The starter electrical circuit on your vehicle doesn't use a relay like that . It's mounted on inner fender . Big thing .
https://easyautodiagnostics.com/ford/4.9L-5.0L-5.8L/starter-motor-wiring-diagram-1

There's this website www.reliable-store.com
They have books on ALL vehicles.
it covers wiring diagrams, electrical diagrams,

fuse diagram, torque specs, PCV, error codes, fault codes, service info, repair info, parts info, owner's/service/repair/parts/maintenance manuals etc everything totally..
I have 1987 toyota 4runner model and I keep servicing and when needed repair it on my own. worth it !!!

Good question. Since most manufacturers don't give routing of harnesses, just generalization. Where they should be. You have to do what most of us do. Pull panels to find the short. Start at the light itself. Check for power and ground in the wire behind the plug.

There are some trucks with a battery disconnect switch. It fails more often than starter. Wires rub through and short/ground out. Corroded ground connections are common. Have the old starter tested.

How much freon goes in my 2007 KENWORTH w900 with sleeper

I had the same problem, make sure your wires are not exposed and shorting on some piece of metal, that could cause a fire. Other than that I would check that starter again, it sounds like it is seized or maybe you have the wires on backwards. If you have an oil leak and oil gets into that starter it will destroy it. Hope that helps!

Sam, this is all I could find, check the link. 1996 T600 Kenworth Battery cable hookup Google Search

All Kenworth trucks are hooked up in Parallel Not series

All the ground jumpers go to negitive and all positive are the same.
Make sure all the connections are clean.