Diff lock switch / wiring

[andrewmacrae]

Hi all,

I'm new to the forum, and a new Puma 2.2 owner.

I've got an issue with the diff lock switch or wiring. After giving the underbody a pressure wash last week, the diff lock warning light started to flicker on and after a while stayed lit. I locked and unlocked the diff a few times and eventually the light went out. It dried out and was fine for a few days, but then I drove in the rain yesterday and now it's permanently lit. I've confirmed the diff is unlocked by jacking a front axle and spinning the wheel freely. So I'm assuming the switch circuit has found earth somewhere.

I think I can identify where the switch comes out of the top of the transfer case, towards the left hand side of the case, connected to one green/yellow wire and one black wire. I can trace the wires back to where they join the loom under the drivers seat, and can't see any broken or corroded connections with a quick visual inspection.

My next thought is to spray some contact cleaner into the switch to see if that clears it -- it's pretty grimy and greasy in that area -- but after that I'm out of ideas.

Is it more likely to be the switch or a wiring fault somewhere further up the line?

And is this even a job for a curious but inexperienced DIYer? The switch looks very difficult to access from underneath the vehicle.

Thanks,

Andrew