j79z28

The other day, I am driving down the street with the vent turned to on, and my blower motor stops working. After reading other posts, I have:
1.Checked the red wire connector under the hood, and the modification has been already done already.
2. checked the brown wire behind the ac/heat control panel. That modifiation has been done already.
3. I have replaced the relay and resistor.
4. The fan motor runs fine when I wire it directly to the battery.
5. I tested the fan motor switch by placing a paper clip in the purple and yellow terminals of the resistor connector, turned the ignition to on(not starting the car), and the fan switch to low. No power per my test light. I did the same test for the tan and blue wires on the resistor connector, and the test light did not come on when I moved the switch on the second and third speeds accordingly.

My question is did I test the blower motor switct on the ac/heat control panel properly, and do you think it is my fan switch that is bad?

Thanks for any advice!!

NINÅ

Using a jumper wire, and a friend, jump 12 volts to the ORANGE wire going to the blower switch and listen for relay clicking.

Report findings.

◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!

j79z28

Hi Nina,
I removed the battery and sat it next to the car. Connected a wire to the positive side, and inserted the other end of the wire into the orange wire where it meets the connector to the blower switch. I did NOT hear a clicking sound. What are your thoughts?

NINÅ

I’m wondering why you removed the battery.

However if the negative side of the battery was connected to a good ground the test is valid.

Due to the fact the relay did not energize, the relay is defective or the wiring to it is.

Now, apply 12 volts to that ORANGE wire again, use a voltmeter to see if you have 12 volts at pin D of the blower relay.

Pin D should be fed by an ORANGE wire.

Report findings.

◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!

j79z28

Hi Nina,
I disconnected the battery because I used it a a source of power to do the test. I just retested everything, and used a better source for a ground. This time, the relay definitely WAS clicking. What are your thoughts now on what could be the issue? I have replaced the resistor as well (cheap part not to replace) and still not luck. Thanks for the help, I hate electrical gremlins like this!!!!

NINÅ

You can keep the battery in the car and connected as you normally would.

That way you can 12 get volts from the cigarette lighter.

You can plug a cigarette lighter accessory plug with wires into the cigarette lighter socket and use the positive lead as a source of 12 volts.

OK, due to the fact the relay clicks, connect the test light from ground, to pin A (RED wire) of the blower relay.

The test light will light if that portion of the circuit is ok.

If the test light doesn’t light the fusible link or associated wiring is bad.

If the test light does light, apply 12 volts to the ORANGE wire again on the blower switch and keep it there so the relay remains energized.

Use the test light to see if there is power on pin E (PURPLE wire).

Report findings.

◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!

j79z28

Hi Nina,

I ran a test light to Pin A (red wire), and the test light shows power.

On the second test, there is no power to pin E, purple wire.

Thanks for helping me, look forward to your reply. I will need to buy one of those adapters for my cigarette lighter.

Jay

NINÅ

OK, because there was no power on E when the relay was energized, the relay appears defective even tho you said you replaced it.

Here’s a confirmation test:

With the relay energized you should have power on pin A&D.

Here’s the next test:

Unplug the relay, use a jumper wire and jump pin A to pin E.

This jump should turn the blower on.

(It does not matter what position the ignition key is in.)

If the blower does not turn on, use the jumper wire below the socket and jump the wires going to pins A&E.

Report findings.

◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!

88 TA GTA

The pin letters A-D are on the wiring harness right were it plugs in to the relay.....