hey everyone,

I have an 89 civic dx and for some reason the heater blows no warm air. I searched around and found that this may be a problem with the power transistor module so i bought a new one and that didn't seem to fix it. It sounds like the fan is not blowing. Any hints or directions to a thread addressing this would be greatly appreciated.


thanks!

 

Check for power at the motor. Measure the voltage between the two motor wires with the motor plugged in, key on, and switch on high.

If you have battery voltage but the fan doesn't run, the motor is bad.

If it's near zero volts between the two wires, measure from each wire to ground.

If you have zero on both wires, check the fuse and relay under the hood. Fuse is in the box near the battery. I think the relay is on the right fender.

If you have battery voltage on both wires, the switch or the ground wire under the dash are bad. I don't think the high speed uses the resistor.