Having trouble with blower motor

[Rokketarm]

My 94 Q45's blower motor for the A/C won't come on unless I hit a speed bump, and then it only comes on at half speed. Any suggestions on where to start, and how to fix??

[Q45tech]

The usual proceedure is to replace the fan motor with a new unit [or if you are trained in electric motor rehabilitation] repair it. Commutator worn and dirty, brush length.

Used junkyard units may be as bad or worse depending on hours of use or local air pollution conditions.

[bullittandy]

This sounds like a bad ground or other wiring problem. Tracing the wiring would be tough but the problem may be fixed by taking out the blower and replacing it. If you do take it out to repair I think any electrical shop could repair it very easily and cheaply.