Was your resister pack burnt out because i have the same problem with the heater and air con not working on 1 2 and 3. i have checked the heater switch which is ok. i have checked all fuses and relays which are ok the only thing i can find is the resistor which appears a little rusty but not burnt out. I am some what confused now and dont want to go to ford and buy all diffrent parts to fault find.

Was the resistor pack blown or not?

Thanks Wipper