Old VW Busses are notorious for their heaters not cutting it. I own a 1965 VW Bus and can sympathize as my own heater is useless. The typical solution is to add an aftermarket heater such as the gas heaters commonly found in the campers. These heaters are sweet! They can tap into the existing fuel tank and run off 0.5 pints of gasoline per hour. They push out a large amount of heat very efficiently.
A couple years ago I picked up a mostly complete gas heater and stuck it on the projects shelf. Well now it is winter again and my usual candle between the legs and a furry parka method for providing personal warmth is getting a bit dated. The heater needed a fuel pump and the pumps run around $240, ouch! I took a look at Craigslist and someone had posted an hour before a complete and almost working heater of the same model for $70! It had a fuel pump and I figured if nothing else I could use parts off both heaters to make one work.
After staring at a wiring diagram with my buddy Josh (pictured) for a couple hours we managed to get my heater running with the help of the fuel pump. The relay was the only part not working but we managed to bypass it. The new heater had a nearly identical issue with the relay being bad and the mechanism triggering the fuel pump needs to be cleaned out.
I now have a working heater for my 1965 VW Bus and will soon have a backup as well!
Time for some winter cruising!