Hi,

My son has a 2000 Subaru Legacy. The fan stopped working on his heather. He replaced the fan with a new one, but it still didn't work. We returned that, just in case it was bad, and got a second one. It didn't work either. We also checked all the fuses and they seem to be fine.

 

With a power meter we confirmed that when you turn the fan switch up, power is getting through the wires to the plug that goes in the fan. Still doesn't work, though.

 

Any ideas? Let me know if you need more information. I can't figure out what to try next.

 

Thanks.

Steve

maybe a ground wire is broken somewhere? something physically blocking the fan/air flow? is there a noise? any chance of rodents building a nest in the car?

Edited February 1, 201610 yr by 1 Lucky Texan

Thanks for the response. There is nothing blocking the motor (animal or otherwise!) and there is absolutely no noise when you click it on. Perhaps it is the ground wire. That is new territory for me. How do you locate and then check/replace the ground wire? 

Fan is grounded through the fan speed switch.

Could be a bad fan speed switch, or a dead resistor block.

 

Resistor is stuck in the side of the air box behind the glove box. Unplug it and turn on the key, see which wire you have 12v on, then jumper that wire to any of the other wires in the plug. Move the fan speed switch to each position and see if the fan works on one speed. If it does, the resistor block is dead. If still no fan, either the switch is dead or the ground for the switch is broken or unplugged. A bad ground isn't likely unless someone has been digging around in the dash and knocked the wire loose or cut it. (such as maybe installing a new stereo)

honestly I can't help a lot here - if there were other electrical problems, I'd suspect a common ground was involved. But some high-ish current devices have their own dedicated ground. A Factory Service manual with wiring diagrams may be required - sometimes you can find pdfs or scans online.

 

someone may chime in here with the info or experience with the fan system.

doh !

 

fairtax to the rescue!

Did you check voltage with the fan connected or disconnected?

If Disconnected you meter can lie to you.

 

Check out Load Pro on you tube.  You will find numerous videos Dan Sullivan has done on properly checking voltage.

- Seeing Voltage in the connector you have ruled out:

1) Opens

2) Shorts

 

You need to check the circuit under load (fan connected) or using the Load Pro to rule out high resistance.

Thanks everyone. I'll try these things out and see how it goes.

The trouble will be with the resistor block alright. It is a common issue. It will be mounted on the air duct for cooling.