I'm not able to run my rear heater (no blower function) on my 83.5 and have gotten it down to three distinct issues:

1. �I've verified that the blower motor for the rear heater core works, but only full-speed by putting 12V to it. �However, 12V to either of the two resister leads yields nothing. �Is that resister (or an easy equivalent) available separately to give me multiple-speeds again? �This test ruled-out the blower being bad, correct?

2. �I get no power on any of the four wires feeding the switch that goes to the rear blower, and can't figure-out which wire represents which lead. �I have Yellow/Black, Black/Yellow, White and Yellow/(Gray?) at the switch socket. �Which one should be hot, and which colors match partial speeds? �All my fuses are new, but the relevant fuse for this blower is...?

3. �When I checked the switch for continuity/resistance (which I did before seeing if it was getting any power), I expected 1-2 Ohms when connected, and instead I get a bouncing number mostly over >= 120 Ohms for each combination. �Switch is original, but leads are absolutely corrosion-free. �Is this acceptable, or do I buy another switch as well?

4. �Since I'm starting to have seepage from valve and heater core back there, is anyone getting rid of one or both in good condition?

Thanks all!
David