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Heater fan speed changes with RPM?

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Okay, So I drove the newly acquire subie to work today. I had the defroster on and the fan on the highest setting. Well when I would accelerate I could hear the fan kick off and complete quit running? :confused: Then once I got up to speed, I could wait say 5 seconds and the fan would slowly start back up.

 

Whats causing this? Is this Common?

 

My old XJ use to have a similiar problem when the AC was on. Turned out the heater Fan was on the end of a wiring run that would tend to corrode so a quick rewire directly to the ignition power fix that problem.

Hmmmm if its on defrost, if you floor it, and the AC compressor was running its possible that it kicked off. My impreza did that.

 

Funny that the fan has issues when you accelerate. Mine has issues when I am sitting still. My alternator at idle isnt strong enough to run front defrost on level 4 AND the rear defrost and headlights and radio.

  • Author

Heres some more info that might help:

 

Rear defroster button was on, but I didn't seem to defrost the rear window????

 

The headlights were off this morning.... but the radio was on.

 

All of the AC componets have been removed. When I got the car the AC pump was gone and the flex lines. Since I'm planning on installing OBA, I decided to remove all the other AC components. (radiator, acumulator, hardlines, AC Core, and I beileve the Core pressure switch) I really doubt this had anythign to do with it but who knows?

 

The push button cluster on the right side of the steering wheel has been replaced with one that doesn't have the AC button. (the one one did but it was all busted up)

if you hooked up a vac line wrong your heater controlls will do wierd stuff, that might exibit the same symptoms. you didnt remove the little canister with the two vac hoses going into it, on the rear of the passenger side strut tower did you?

 

are you sure the fans turning off and not just switching ducts?

  • Author

SOB - I've typed this reponse twice now and the computer keeps screwing up and loosing it!!!!! ARGH

:banghead: :banghead: :banghead: :banghead:

 

Try 3

 

if you hooked up a vac line wrong your heater controlls will do wierd stuff, that might exibit the same symptoms.

I'm 100% positive its right. all the numbers matched up and I double checked it.

 

you didnt remove the little canister with the two vac hoses going into it, on the rear of the passenger side strut tower did you?

Nope, its still there. Whats that called and what does it do? kinda looks like a Subaru after thought to me.....

 

are you sure the fans turning off and not just switching ducts?

Not sure. I guess it could be doing that.

 

I tried to reproduce it today at lunch but I couldn't get it to do it. I know its done it twice on me so far. And I've only driven the car 4 times now. o the odd apear to me that there is a problem.

I have hed vehicles in the past where if I was putting the vehicle under strain (ie: up a long hill) it would automatically reduce/cut power consumption to take the strain off the alternator, to help divert power to the engine...

 

don't think soobies did this, but I'm used to the ea81.... if my 87 was running, I'd be able to check it out.....

Nope, its still there. Whats that called and what does it do? kinda looks like a Subaru after thought to me.....

Its a Vacuum reservoir, it stores vac so the heater/vent/defrost settings hold at low or no vacuum conditions (like heavy acceleration). It has a check valve (internal or external, I cant remember), if its not working correctly things will act strange, I think VENT is the default (no vac) setting.

Gary

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