Ole BlackBetty
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My air fan suddenly started blowing only on high. Is there a fuse or something that maay be causing it not to blow on slower speeds?
Ac / heater fan
- Thread starter Ole BlackBetty
- Start date
Blower resistor. Should be located in the fan box. They way these work, is there is various sized resistors (coils of different sized wire) which controls the amount of power getting to the fan motor. Hi is a straight 12 volts, no resistors. Once you get it dug out, you will find one or more contacts are rusted/burnt through.....
This is just and example I stole off the internet...
This gives you an idea of what you are looking for....
This is just and example I stole off the internet...
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This gives you an idea of what you are looking for....
cheap bronco
Full Access Member
Does this mean that if we get a different resistor from a superduty or crown vic we will be getting more cfm from our fans
IDIBRONCO
IDIBRONCO
I believe that if you can spin your fan faster, you should get more cfm's. A different resistor probably won't make it spin faster, it cuts down the power to the fan to make it spin slower. That's how it gets the different speeds. Get a faster spinning fan motor or get a bigger fan to fit in your heater box. That's how to get more cfm's.
cheap bronco
Full Access Member
From other posts I understand that a fan from a t-bird would work. Can anyone confirm?
79jasper
Chickenhawk
Yeah, other full size cars also. But a lot said it didn't improve much.
I think main thing is going from a worn out motor, to a new motor.
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I think main thing is going from a worn out motor, to a new motor.
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X2 on that...and, in some cases, the resistor pack going out is a symptom of a failing fan motor. There is a fuse in the resistor pack, and if the fan's drawing too much current, the fuse will let go and make the resistor pack go dead...which will give you nothing on any fan speed setting other than HIGH (which bypasses the resistor pack completely).
If you pull the resistor pack out and don't see any obviously rusted/broken connections, I would seriously consider pulling the fan. Check the plug and see if there's any distortion, then see how the fan spins. It should spin pretty freely...if it doesn't, it's time for a new fan. You might be able to grease the bearings and get a bit more life out of the fan, but that'll only buy you so much time...
Ole BlackBetty
Full Access Member
Thank you all for your replies, I will pull the fan when I get a little time and check it out
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See that round silver looking thing that looks like a capacitor? That's a thermal fuse, just like they put in coffee makers. I have seen these open up and cause the fan only to run on high. If your resistors look good, then I bet that's the problem. If you take a ohmmeter and read across it, you should get continuity. If it's open, make a jumper to go across it and see if your fan works then. It's up to you whether you want to replace it properly or leave the jumper in place.
jim_22
Full Access Member
Great timing, mine started doing exactly that yesterday!
jim_22
Full Access Member
and now for the dumb question... Where is the fan box on a 94? I expected it to be next to the fan motor like I have seen in some pictures. Under the dash? Behind the glove box?
man i just want a fan out of somethign newer that will bolt in ish. I put a new resistor on mine, fan spins freely but evne on high it is JUNK. and the other 3 speeds it barely barely spins. Maybe need a new fan, but would rathe rupgrade to somethign that will actually BLOW WIND.
You would be surprised how good the original style system is if it's in good shape. I had a old 1980 f150 that had the same problem, and I could barely get the windshield defrosted. A couple of years later I took the duct system apart to put a new coil in for the A/C to get it working again. You would not believe the pencils, and other junk I got out of the duct work, and the A/C coil looked like someone took hair and mud and smeared over the whole thing. Once I replaced that and clean out the debris from the ducts, it would run you out of the cab in the winter. Believe me, the original system in good shape has plenty of capacity and WIND.
