Fan not working on dash heater

[bobcre]

I have this 1985 Pinnacle By Establishment with a 454 chevy engine the fan for the dash heater dose not work and having trouble tracing down with out wiring diagram if anyone has any ideas would appreciate the help can't seem to find any info on it Thanks

[BFlinn181]

The fan switch on the HVAC control sends power to a resistor pack that uses resistors to control the different speeds. When the resistor pack goes bad, it typically only effects one or two speeds. It's often under the hood or inside the heater plenum itself. If you have no fan at all, it's either the fan motor or the dash switch. Testing for power coming out of the switch would identify if it's bad. If you can't get to a connector, use a straight pin to pierce the wire to test for voltage.

If you have power coming out of the switch, next use jumpers to connect directly to the fan wires. If it doesn't run, pull it and take to an Auto parts store, they can probably match it up.

[wa8yxm]

I keep reading about that resistor pack.. Fact is if the fan does not work AT ALL, it is NOT, and I can prove it NOT the resistor pack.

Why do I say this.. One of the wires on the resistor pack has two leads hooked to it. .This is the HIGH speed. one is "HIGH" and the other is the motor.. So HIGH will work even if the pack is bad.

On GM designed systems there are also 2 relays Low speed and High Speed, I have no clue where. And the switch itself (Had one of those fail on a car)

And there is the ever loveing FUSE. which on my coach was NOT the fuse labeled for the HEVAC but another one entierly.. With some help from OMEY's web site and the diagrams there I found the HEVAC is supposed to connect to the accessory convience terminal which on my coach is near the parking brake.. The terminal for the HEVAC was, however, vacant (power to it but no wire on it) Thankfully Damon or Workhorse, NOT SURE WHICH has a habbit of printing the function ON THE WIRE,, So there was a yellow wire that said HEVAC or AIR Conditioenr (Forget which) plugged into a DIFFERENT terminal on that same board.. This lead me to a circuit breaker,, An new breaker to replace the broken one and AHH.. (At the time (August) HEAT was not want I wanted but man did that COOL feel nice)