Just came across this thread but thought I'd kick it into life again!
I had a wire shorting out and blowing fuses on a Massey 6160 ( no surprise there)
The fuse would blow when you got in the cab or sometimes while driving.
When I tried locating it by jumping on the steps and pulling at the wiring loom I soon had a pile of blown fuses a foot high lying on the floor and was pulling my hair out
So.... a light bulb moment, literally!
I connected a 12v bulb to the fuse socket and instead of blowing the fuse whenever it shorted out the bulb lit up! (I'm sure there's a few good technical reasons not to do this but needs must....!)
This allowed me to trace the fault by moving the loom and replicating tractor movement and I soon discovered the worn out sheathing and shorting wire!
Happy Days!!!
