I have a 92 legacy, two weeks the heater blower died, it had a noise for the last 5 years, Last week I replaced it with a used unit, that I cleaned up and relubed the the shaft bearing area with some grease it ran great for a week. today that motor is now dead. Is there something that could make this motor go bad, the fuses are ok. Before I spend 80 on a retail motor I thought I would ask. or is it bad luck?

Have you tested the input voltage at the blower motor connector with a multimeter to see if there is anything abnormal there?

No, if the motor is on a fuse wouldnt that regulate any overvoltage. thank you

5 years of squeaking prolly didn't do the windings or contacts any good. If it were me, I would replace with one from a wrecking yard.

No, if the motor is on a fuse wouldnt that regulate any overvoltage. thank you

 

Fuses protect electrical devices by limiting the current through the device and circuit, not voltage.

 

If the blower motor doesn't work at any speed then check to see if voltage is getting to each side of the motor connections using chassis ground as the meter reference and with the speed switch set to high. If you have 12 volts on each side of the motor leads then you most likely need to replace the resistor pack that is mounted on the air duct. If there is voltage only seen on one of the motor leads then the motor is bad.

 

The way the circuit is designed is fused power goes to a relay, then through the motor, through the speed switch, and then to ground.

Edited December 24, 201213 yr by Cougar

The motor I got from the parts guy died after a week, so I am looking to do motor #3 now. I think I have something to test voltage will get back when thats done. thank you

You might want to check your alternator. When the internal regulator goes haywire your alternator will produce far to much current and systematically start burning up electrical component's. My son in law had a 1985 ea82 wagon that was burning out stuff. He installed a different alternator and had no further problem's.

The charging voltage shouldn't exceed 15 volts DC and the AC voltage should be less than .1 volt while the engine is running 1500 RPM.

No, if the motor is on a fuse wouldnt that regulate any overvoltage. thank you

 

That's not how fuses work. Fuses limit current (amperage) by burning out. Check the fuse for the fan. If its blown, it's probably because the fan was pulling too many amps, which means its not any better off than the old squeaky one.

I now remember that about 2 years ago the fan had a problem where it would not work when the car first started up but after a few bumps it would work fine. For the last year it was ok every day.

 

When I replaced the old fan 2 weeks ago it was totally dead, I plugged the new one in and it ran fine, so I that the old issue is related to the current problem but I cant be sure.

 

I will have a voltmeter tomorrow, do I test the voltage across the plug? Does it vary with the fan settings? Will also test the resistor, it says to test across the contacts, but which ones? I think there were 4 or 5 of them, just pick one and test the others against it? Thank you for your help, I need it!

Edited December 25, 201213 yr by ron2368

An easy way to check the voltage going to the blower is to check it at the fuse. Place the common probe of the meter to a good ground point on the chassis and the other probe on one of the slits on the top of the fuse. Don't worry about checking the voltage across the resistors. If the blower doesn't work then check the voltage at the motor connections while the blower is connected. See if there is voltage on the leads using ground as your reference and checking one lead at a time. If there is not voltage getting to the leads then the blower relay needs to be checked. If both leads have about 12 volts on them then the trouble is most likely with the resistor pack. If only one lead has voltage getting to it then the motor is bad. You could also verify the motor by applying power directly to it from the battery.

Edited December 26, 201213 yr by Cougar

check blower realay

I looked under the dash for the relay and could not find it, is in engine compt? My manual mentions it but does not say where it is.

The relay is under the dash and is near three other relays if I recall correctly. I wouldn't bother checking the relay unless you find there no voltage getting the motor leads.

I have a new relay, I tested the voltage at the fan clip and there was none.

I still cant find the relay, the part I have is 35767 and is a air conditioning relay. I see other boxes under the dash but they are plastic and the one I have looks like it should be out by the engine, though I still cant locate it there.

I have the wrong part, I liked it since it was 8$ , the correct part is 90. Its r6154 , I am going to check the plug pattern before ordering

 

Later that day> plug pattern was wrong so I ordered part from local subie dealer. They used vin to find part so hopefully it solves my issue.

Edited December 27, 201213 yr by ron2368

Well hopefully you haven't jumped the gun in ordering parts that you haven't yet proved are bad.

 

The info I am looking at shows there are a few relays in the upper far left side of the dash area. The blower relay should be one of them. I assume that when you made the voltage test that you had the fan switch turned on to some sort of speed setting, otherwise the test isn't valid.

I did the test at least 3 times, there is no voltage to the fan. I checked the fan resistor per the manual and it was ok. The wiring diagram shows a bl/red wire that goes to the relay from fan. I can follow it up to a large mass of wires where it looks like it turns left. Yes there are two plastic small boxes right next to eachother one has 2 or 3 wires the other has 5 so I guess I will find out when I get the part. The fan wire is fairly thick but the wires to these boxes is much thinner, hope it does not matter.

One of the wire colors going to the motor should also go to the proper relay.