Ok so I was driving home in the rain and had my wipers and heater/defroster on. Suddenly the cab was full of thick black smoke. Pulled off the road and used a tree to stop me from 50 to 0 in an instant. Jumped out thinking I was avoiding a fires but no. Just lots of smoke. Everything was working fine. All lights wipers engine. Everything fine. Im thinking maybe heater blower motor. I turned the truck back on. Started first time. No smoke. Turned on components one at a time no smoke until I turned the heater on. Came pouring out of the vents. Smelled like burning pine needles. Anyone have any ideas? Good news is absolutely NO body damage from slamming into that tree. None. I love my tank!