The AC/Heater Blower on my '86 only works on high speed intermittently. It will not work at any other speed. Fan test ok. Replaced switch with same results. Is there a relay somewhere I am missing? I am a newbie, by the way.

my best bet is that your problem is the blower motor resistor

Do you know where that is located?

i am sorry, i do not. if you call a dealership (parts department), they should be able to tell you if that is a common problem, and they should have schematics of where it is...