My S3 never had a functioning heater and after finding out what a stock heater core and fan motor cost, I decided to fit a generic heater. The heater I used is a 28,000 BTU model from summitracing #991102 ($135). Its made by Heatercraft and is made to fit basically anything from RVs, boats, jeeps, buggies, you name it. It comes with a 3 speed motor and 3 row heater core . Also comes with a switch, wiring, and brackets. I thought about installing it inside the cabin, but the space is limited underneath a series3 dash. So I decided to mount it where the factory stuff was and it fits pretty good there. The only modification I had to do was block off the 2nd duct in the heater and weld a bracket to the top of the heater box. I actually used the 2nd duct opening that I cut out and put that where the square hole was on the bulkhead. Then I connected the 2 with 3" flexible HVAC ducting. I wired up the switch to my S3 hazard panel. The airflow comes into the stock location so the vents and defroster work the way they did before.
Before:
The new heater stripped down:
Close up of the new 3 row core:
Installed! I mounted it to the stock holes where the old heater box was. I also bolted it to that side bracket thingy:
I have tested it out yesterday here in Central Pennsylvania for a few hours. It was about 34 degrees and I felt comfortable with the heater on Low. Im also missing a few door seals and I have a softtop! Cant wait for a real test!
