Ac fan always on high

[broomhandle]

It seams like my ac fan is always going full speed. I don't think it's normal. Any thoughts?

It's a 2.8 with 77k miles.

[(Batman]

Your switch (speed control knob) could be broken.

Does it still blow even if you switch the speed to the off position?

[autotragik b3attlewagen]

ac blower resistor needs to be replaced.

OE part number: 8D0959263
here is the listing from ECS: http://www.ecstuning.com/Volkswagen-...Search/Blower/

[broomhandle]

sorry, im talking about the fan in the engine bay. you know like when its hot out and the aux fan kicks on. it seams like its always going....

the blower works fine.

[scotts13]

sorry, im talking about the fan in the engine bay. you know like when its hot out and the aux fan kicks on. it seams like its always going....

the blower works fine.

I suspected as much. Believe it or not, the most common cause of this is people confusing the temperature sender and the thermal fan switch. Have you replaced either recently? The sender lives at the upper rear of the engine, and the switch at the lower corner of the radiator. Several people have installed the sensor where the switch belongs, and presto! the fan runs full speed all the time.

Failing that, you may have a bad thermal fan switch, or (more annoying and expensive) a bad fan control module.

[broomhandle]

I suspected as much. Believe it or not, the most common cause of this is people confusing the temperature sender and the thermal fan switch. Have you replaced either recently? The sender lives at the upper rear of the engine, and the switch at the lower corner of the radiator. Several people have installed the sensor where the switch belongs, and presto! the fan runs full speed all the time.

Failing that, you may have a bad thermal fan switch, or (more annoying and expensive) a bad fan control module.

i just got the car, so i dont know....

crap, where to start.....

[scotts13]

crap, where to start.....

With the thermal fan switch. Cheap, and easy to replace if you don't mind losing a little coolant.

[broomhandle]

With the thermal fan switch. Cheap, and easy to replace if you don't mind losing a little coolant.

so i guess check 1st on the radiator if its a blue switch. and replace it anyways.

now, which brand....

i use uro parts on my porsche 914's, but i know they are a bit cheaper quality....

[W8sted03]

I ran into a similar problem. After 3 trips to the dealer, we finally replaced the thermostat. That visit ran me about 1200 bucks. But that was also on a W8. I wish you a cheaper and speedier solution!

[broomhandle]

I ran into a similar problem. After 3 trips to the dealer, we finally replaced the thermostat. That visit ran me about 1200 bucks. But that was also on a W8. I wish you a cheaper and speedier solution!

the car never overheats though. even in 100+ degree days. its just always spinning high speed, even in the cool of night.

[W8sted03]

The car doesn't need to overheat. Neither did mine. But the fan was on all the time and it sounded like a UFO. The thermostat got stuck in the "on" position. It was a mechanical defect from the factory.

[broomhandle]

crap, and thats prob not a DIY thing.

i might start with the blue plug because that is cheap and easy.

[scotts13]

crap, and thats prob not a DIY thing.

Note that W8sted03 has a W8 Passat, a completely different engine with a different thermostat/fan control setup from your car. The thermostat for his car is $500. For yours, maybe $30.

[W8sted03]

Note that W8sted03 has a W8 Passat, a completely different engine with a different thermostat/fan control setup from your car. The thermostat for his car is $500. For yours, maybe $30.

Yeah, I definitely paid to have mine replaced...but the car runs well for the most part. I have that thermostat saved in a box. I figured that even a busted one might fetch some loose change a few years from now

Good luck on the fix. Let us know what you find.

[broomhandle]

hi guys,

i have looked and looked when i get time, and i can not find that blue switch. is it on the left bottom side? on the radiator? or on a hose?

i might just have my local shop do it. was trying to save some $$$.

its like a 10.00 parts. but prob an hour to change it out.....

[broomhandle]

so i took my B5 into the shop, and they told me my fan is normal. it just runs like that when the AC is on. it just seams so loud. and the AC has been on because its been so hot.

comments?

[W8sted03]

I would agree with the shop. That "ufo" sound I was telling you about, mine only kicks on now (now that it's fixed) when I turn my ac on. Then again, I have a completely different sense of what to expect out of my car. Any other takers?

[scotts13]

The fan will be on when the AC is activated, no question. It shouldn't be on the "high" speed unless the engine needs additional cooling. When I first got into B5/5.5 Passats, I was surprised how loud the electric fan is, so it's possible it's not actually on high.

[broomhandle]

The fan will be on when the AC is activated, no question. It shouldn't be on the "high" speed unless the engine needs additional cooling. When I first got into B5/5.5 Passats, I was surprised how loud the electric fan is, so it's possible it's not actually on high.

haha. then maybe just a really loud fan. maybe we should find a better one! haha