Spontaneous electrical fire


New member
I am not a tech person so pls forgive my lack of correct jargon.

We have a 1990 Westy camper van. It has an aux battery.

A few weeks ago as the van was parked we noticed a clicking noise inside the back left ( driver side) corner. Nothing was switched on. The clicking stopped when we pressed the brake pedal, we assume because the brake lights drew the last of any battery power.
We should have thought to uncable the battery right then, but alas!

The next morning there was a haze and bad smell in the van, but no clicking.

We aired it out. That evening the clicking was back and there was an acrid smell. We found that there had been an electrical fire in the left upper rear cabinet (where the AC system wiring is, so i'm told.)
We smelled burning and saw scorch marks.
Finally we unhooked the battery.

So, the mechanic (a very reputable westy expert), will remove the cabinets and repair/replace the wiring, but how in the world does the AC system burn up without being switched on???? How did the relay (or whatever was clicking) be engaged long enough to start a fire?

The mechanic figures the AC freon actually put the fire out and that was what the haze was the morning of the fire.
Can't find another instance of this anywhere. I hesitate to spend the major $$$ to fix the AC system before we know the cause.
Thanks for your ideas!