Have you checked to see if you've had water intrusion? I just had a very similar issue with mine and I ended up finding a lot of my issue were due to deteriorated factory splices. In the meantime since you don't have an IID tool yet i'd check as much as you can without it. I'd focus on the wire splices in the PS floor behind the kick panel and running down into the door sill.

 

I'll look into that, tank you!

 

...no wonder the LR3 has class-leading water fording capability, because if it DOES get into the cabin, you're screwed!

 

Right? Who's bright idea was it to put critical electrical splices under the door sill?

Is there any easy/cheap way of protecting these lines?

 

Would silicone caulk work for the wires laying in the floor channel?