Massey 4200 series - wiring issue

patsy_mccabe · 12-03-2025 03:14PM #1

Another wiring problem.

A neighbour has asked me to look at his 4235 Massey as it's running down the battery.

When stopped, I'm getting 12.5v from the battery earth stub to the disconnected earth lead. That to me is a live earth somewhere but not enough to blow a fuse.

How can I trace the fault? I've taken out most of the fuses, disconnected the radio. No good. All wires seem impossible to trace.

Anyone have a wiring diagram?

FintanMcluskey · 12-03-2025 07:57PM

Alternator?

patsy_mccabe · 14-03-2025 08:55AM

No I disconnected the alternator and the 12.5v still there at the earth terminal of the battery.

DBK1 · 14-03-2025 10:08AM

https://www.boards.ie/discussion/2058402217/massey-4200-series-wiring-issue

I was changing a deadman on one of the tractors here and realised I’ve the very same problem so I’d be interested if you find a solution to it. With the earth wire disconnected from the battery I’m still getting 12.5 volts if I put the multimeter on the positive battery terminal and to the chassis of the tractor.

patsy_mccabe · 14-03-2025 10:24AM

What do you get from the disconnected earth lead to the earth of the battery?

DBK1 · 14-03-2025 01:29PM

https://www.boards.ie/discussion/comment/123263430#Comment_123263430

I didn’t check that. I’ll try it later today.

blue5000 · 16-03-2025 09:55AM

I think some of the deadman switches aren’t great, try putting a vice grip or clamp across the cables to the deadman. They go rusty inside where the contacts are.

Massey 4200 series - wiring issue

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