Just hoping someone can send me a link or let me know how to get at the transistor for the blower motor. I went and bought a new motor thinking that was the problem and turns out it wasn't so I want to check the transistor, but can't find it. Help please!

Thanks
Jason

 

OK so I've checked the 40 amp fuse under the hood and its good, I've checked the resistor and it's good and I've checked the blower fan and it is good. Anyone know if there is something else that would make the blower fan in the civic not work? Frustrating.

Thanks for any help.

 

If your getting voltage at the blower motor connector then check the ground.

If you're not getting voltage at the motor check for voltage at the resistor connector. If no voltage at the resistor then it's probably the switch module.

 

1. How did you check the blower power transistor and determine it was good?

The blower power transistor module usually consist of several components: transistor, thermal cutoff, resistors, and capacitor.

2. This next test will be used to rule out the blower motor relay and a couple of other things, to help narrow down the problem area.

a. Unplug the electrical connector to the transistor unit.
b. Attach a jumper wire (short piece of wire) from the Grn wire cavity (No. 4 terminal) to the Black wire cavity (No. 2 terminal) on the unplugged electrical connector. Leave the connector unplugged.
c. Turn the ignition ON, does the blower motor fan run?

3. If the blower motor runs in the test in #2 above, then the problem area can be narrowed down to the following:

- Blower power transistor
- heater control panel
- wiring

4. To check whether there is power going to the blower power transistor, you'll want to backprobe the Yel wire that runs from the heater control panel to the transistor.

Backprobing is either using a backprobe set or using a thin needle or something and making contact with the metal terminal of the connector without piercing the wire in the back of the still connected connector. Care must be taken to ensure that the wiring does not get damaged. You can use something like a T pin, available at Walmart, etc., and backprobe.

At the blower power transistor connector (with it plugged back into the transistor), with the voltmeter’s black lead touching chassis/body metal ground, use the voltmeter’s red lead to backprobe the No. 1 terminal Yel wire. Turn the blower fan setting to the highest speed. There should be ~ 12 volts at the Yel with the ignition turned ON.

If there is ~ 12 volt power at the Yel wire, the fan should run if the blower power transistor is good.