Pontiac Repair: heater blower working intermittently, pontiac bonneville sse, pontiac bonneville

Question
We have a 1993 Pontiac Bonneville SSE with Climate Control. Sometimes the
blower fan does not blow air at all. Even when the electronic squares are all lit
up indicating it is on "high",  and even if it is good and "warmed up". Then
maybe after a trip to town and back (1/2 hour or more of driving) it might
kick in and blow. On other days it might blow right away. The rest of the
heater controls, heat, air conditioning and all, etc.. works good.
Why might it do this? If something needs replacing what, and where could I
find it?

Thanks!

Answer
Hi Mike:

well it can be a motor issue, a control module issue or a blower control module issue. You have to see if when the motor is inop if the motor indeed is getting power and ground. If the motor is missing power or gound you have to trace it back to the where it's missing it. the way the system wors is you selsct the blowr speed the contro lhead sends the request to the blower control module and then that sensds the proper speed signal to the motor. You could have a motor that has a dead spot on it and when you hit a bump it starts to work. You could have a bad connection at the blower control module Which is under the hood on the top of the heater box. It can be a lot of things... It's just a matter of seeing what your missing as to why it's not running. I don'r mean to jump around but there is a lot to this other than just the fan motor and the control head. good luck :)