MF 1533 wiring diagram

stumpfield · Sep 1, 2020

Tractor won't start. It's Challenger MT265 which is a twin of the MF 1533. Tractor has just under 400 hours.
I have eliminated the battery and neutral switch.
There must be some wiring issue or my wiring harness is bad. I was able to crank and start the tractor by jumping the starter by apply 12v to the solenoid.
High resistence (30 ohms) between the battery and the fuse box. I measured 12v at the fuse box. However, as soon as I turn the key, it drops down to about 9 volts. No voltage drop at the battery. Only at the fuse box. I looked everywhere I can see, no broken/loose wire or any corrosion.

I'm hoping someone here have the same tractor with a wiring diagram so I can understand where each wire goes.

Thanks in advance for any help.

Roadworthy · Sep 1, 2020

A diagram will give you the source of the wire and its destination. It won't tell you how it gets from one to the other. Lets start with the basics. You should have the battery load tested. Most places that carry batteries can do that. Thoroughly clean your battery terminals and the connector ends that attach there. If you have clamp on type terminals look for corrosion at the clamp. Secure the connectors tightly on the battery. Now follow the ground lead to the frame. Clean and tighten that connection, too. When all this has been accomplished we can begin to troubleshoot.