Two speed reversible 12 volt. It actually has 5 wires, but I'm sure you could make it work if the motor would physically fit the heater. The label is a little fuzzy in the pic, but i can make out FASCO. I think I've got a FASCO catalog here in my office somewhere. Maybe i can find the OE part number and you can source it somewhere else for less $$$$.
Joe, how do you find these things?? 120 is a little steep, but at least i know they are making them! but one thing i started to think about tonight is what kind of switch to use? I would like to find one that will fit the original hole, but not be ugly. The original switches are great except they do not get along with 12v due to that resistor
What can I say? I'm just a resourceful kind of guy! I remembered seeing it last winter when I was digging around trying to find a suitable 12V replacement for the Magic Air heaters. Oddly enough, Sacramento Vintage had that, too. Give me a little bit and I may be able to find that same motor elsewhere for less cheese. You could probably reuse the original switch and route the current for the slower speed through a remote dropping resistor. There are all kinds of them available from the various OEM's. That's the easy part. Motor first, switch later.
OK, the FASCO part# of the exact motor that SacVin is peddling is 2807-510-146. It looks like that motor fits school bus heaters and is fairly common. The cross reference is Grand Rock part# GR157. Here's a link to their website with all the motor dimensions:
A ground? Some heaters are mounted in a plastic case, no good connection to ground.
Most of these motors have a dedicated ground wire in light of the possibility that they will be mounted with rubber shock mounts - negating a good through-case ground. In heaters like ours that wire was simply attached to the metal heater case with a sheet metal screw.
If this heater is isolated, the wire could be extended outside the case and have a bullet connector to attach.ground it to the firewall behind the heater.
If you look at the picture link directly from SacVin's website at the link I listed above it lists what combination of wires will do what. If I remember correctly, the black wire isn't a ground. It's actually used for one of the speeds. I think the difference here is that this motor is actually wound to provide two different speeds in each direction without a resistor at all. I also ran across a single speed reversible 12V motor with three wires when I was searching for that one. It might be electrically closer to what you actually have, but you'd need a resistor for a slower speed like the original setup.