[DanEC]

Well - I removed the heater motor today and ended up completely disassemblying the motor. There isn't any multi-speed option on the motor. There are only two leads - ground and power. I took the entire thing apart thinking there was a second power terminal inside, but there isn't. Apparently ERA has changed heater sources since the last manual upadate on this.

The only way to come up with mulitiple speed is to wire in a big resister like most older cars use but most are mounted internal to the heater case so as to prevent an exposed, hot resistor that could be touched and there just isn't enough room for one. I checked into a variable resistor but most are for low watt or AC house current - couldn't find a 12 volt one.

Good news is that I put rubber washers top and bottom on the motor mounting screws to the case and now the fan and motor are a lot quieter - so I'm quitting while I'm ahead and haven't broken something.