A/c & heater fan not working

[b_hickman11]

The fan has been working off and on for the past few weeks. I have checked all fuses and they are all good. Tonight it would not blow for about 20 minutes and then all of a sudden it started working again. Once it comes back on it operates normally. I have also pulled the cabin air filter out and visually inspected the fan blades to make sure nothing was nothing stuck in the unit. Any suggestions?

[CTScott]

It could be the motor going bad or the HTR relay, which is located within the bowels of the body ECU.

When it is not working try carefully spinning the fan to see if it then continues to run.

[b_hickman11]

I tried manually spinning the fan with my hand to see if the motor was just getting stuck but that didn't do anything. When it is working it works at normal speed. When it's not working and I turn the knob from off to on, I can hear a "click" sound coming from underneath the steering wheel/fuse box area.

[CTScott]

I tried manually spinning the fan with my hand to see if the motor was just getting stuck but that didn't do anything. When it is working it works at normal speed. When it's not working and I turn the knob from off to on, I can hear a "click" sound coming from underneath the steering wheel/fuse box area.

The click is theoretically a good sign that the relay in the body ECU is alive.

Try running it just on the highest setting, which bypasses the blower resistor (which is responsible for lowering the speed and has an internal fuse).

Do you per chance have access to a multimeter?

[Bluevitz-rs]

Maybe the relay has bad contacts.

[CTScott]

Maybe the relay has bad contacts.

Exactly. That's why I am asking if he has a meter to check the output.

[b_hickman11]

Yes I have the meter. Where do I need to check?

[Bluevitz-rs]

I'd first check and see if you even have any voltage at the motor with the fan switch on

[b_hickman11]

During one of the times the motor is working or during one of times it's messing up?

[BLH]

Both working and not working. Would allow you to compare them.
Not working would be the one to test if you didn't do both.

[CTScott]

Yes I have the meter. Where do I need to check?

Pull the two pin connector off the bottom of the fan motor (above the passenger footwell) and measure the voltage between the two pins. Black is + and blue is -.

Ideally you want to measure it not working, as working it will obviously have power there. The question is if it has voltage on the black wire when the fan is not working.

If it does, then plug the connector back in and also measure the voltage on the blue wire with respect to a chassis ground (bolt into metal under the dash).

[Bluevitz-rs]

Well if the fan is spinning it's pretty obvious there's voltage there... If you turn it on and there no voltage at the fan you start tracing back being carful trying no to disturb the connectors. The worst thing to do trying to diagnose an intermittent problem is wiggle everything around because if there a bad connector it just makes it harder to find. But seeing how the fan circuit is fareley simple it's easy enough to check all connections.

[CTScott]

Well if the fan is spinning it's pretty obvious there's voltage there... If you turn it on and there no voltage at the fan you start tracing back being carful trying no to disturb the connectors. The worst thing to do trying to diagnose an intermittent problem is wiggle everything around because if there a bad connector it just makes it harder to find. But seeing how the fan circuit is fareley simple it's easy enough to check all connections.

With a high current device like the fan, a connection issue is not likely the issue, as a poor connection with high current results in the generation of heat and melting of connectors.

[JEdlinger]

I know this is an old thread, but it EXACTLY describes what is happening with my car. Did you figure it out?

[CTScott]

I know this is an old thread, but it EXACTLY describes what is happening with my car. Did you figure it out?

I never heard an update and the person with the issue has not been on here in over a year. I suggest trying the same tests as we described above.

[scoobopdan]

I'm having the same issue and plan on replacing the fan soon. I've seen some random links to good places to check, but the threads and links are old and outdated. CT, do you have a good online resource for something like that?