Electrical Issue - Dodge Sportsman B300 Camper Van

Hello all,

I'm wondering if someone can help me figure out this electrical issue with my camper van.

It all started on a warm July evening . . .

I had bought the van the previous December, drove it many miles with no issues whatsoever. Then I'm driving East on I-80 out of Denver, the sun sets and I put on the headlights. About an hour later, the engine cuts out, and the compression blows a HUGE backfire out the tailpipe.

I pull over, raise the hood and start fiddling around with battery cables/wires and the auxiliary battery and switches in the back of the camper. Eventually it starts up, and gave me no issues pretty much the rest of the summer.

Now more recently, I believe I've definitely correlated the problem to the headlight switch. I've had it to my mechanic now for the 3rd time. Every time he reassures me it's fixed. And it works great, til the sun goes down.

Here's how it goes down. Now the minute I turn the lights on, the engine cuts out. Then I pull over, and it starts right back up. THEN I finish driving wherever I'm going, park it, and the NEXT day - NOTHING! I turn the key, and it doesn't make a SOUND. Nothing.

The mechanic replaced the ignition switch thinking that was the issue. But it still does the same thing. Tired of having it towed back to the mechanic every few days.

Anyone got a clue what's going on here? Any help would be TRULY appreciated. Ski season is coming and I have to get this thing on the road and running reliably!

Thanks,
Chris from Colorado!