Dan J.

Hi,

I have a 1990 C2. I've had the car for a few months now, and there's one strange thing about the climate control that I can't figure out. Even with both ***** turned off (all the way counter-clockwise), there's a cabin fan that always seems to be running on low speed when the ignition is 'on'. The fan is just barely audible, to the point where once the motor is running the fan can't be heard. It is as if the '0' selection is '1'.

Question: is that fan supposed to run all the time? If so, is there any way to override it?

BTW, this is just a tiny, niggling little issue with a car that overall is great.

Thanks in advance.
Dan J.

ormy

What you are hearing is the sampling fan. This "samples" the air to determine the heating/cooling requirements of the cabin. It also runs for a few minutes after the engine is switched off.

Johnny-Cat

Mine does the same thing, and I would also like it to end! It seems that the 0 position is the same exact speed as position 1. What is the deal, what part has failed?

Dick964

Nothing is wrong.

Two noticable things:

- At the back of the CCU is indeed a small fan which is blowing interior air through the CCU unit (and through the interior temperature sensor..). This small fan will keep running for about 20 minutes when you turn of your engine.

- The other fan mentioned is always running even when you turned it to "0".
This is normal and is even required by law in Germany because there must always be fresh air entering the interior (yes, that sounds strange ; I've read it in Adrian's book).

Regards,

Dick964

R6XTERRA

^^^^^ It is absolutely ridiculous and even with the vents shut, it gets ridiculously hot in the cabin. Especially with our 30 plus degree weather. I may just rid the heater all together since my car is a nice day only car.

MisterRisky

R6X, I'm not sure, but I think you may be talking about another issue. The fan that is required to be running is not the heater fan, its the fresh air vent (assuming you have your temp control set to cold). If you are getting hot air then you have an issue unrelated to the constantly slowly running vent fan.

Dan J.

Well, I figured there must be a good reason.

It's annoying to think that I'm loosing all that juicy HP due to a fan.

In order to offset the HP loss and noise produced by the fan I have installed a cat bypass and g-pipe.

Thanks all,
Dan.

R6XTERRA

Both my 964 did the same thing. My first P-car the air did not work. My second P-car the old PO payed $4600.00 for the air conversion. I have the recipets, I was shocked. It is converted and does not blow cold. I have to get this checked.

None the less, it still blows very warm air through the vents, very small amounts get through but its hot, very hot. Yes, I have the temp set for cold.

It is obviously more noticable on the hot days.

Jeff

C4Russ

You may have a failed air mix valve. It could be stuck in heat position which would allow for heated air to enter the cabin. The car is not right. Nothing wrong with the design, something on your 15 year old car has failed.

MisterRisky

C4Russ is correct. If hot air is coming through the vent, then somehow it is getting past the mixing valves. Here are a few options:

1) Failed mixing servo - diagnose by looking to see if the servo moves
2) Mixing arm adjustment - are the arms set so that at full cool they move too far and actually open up the mixing valves - visual inspection
3) Servo loose - Are the screws holding the servo in place loose allowing the servo to flex and not completely close

I had #3 and it was a PITA to diagnose. But it was a snap to fix. I shot a quick video of the linkage and how the servos work. Maybe this will help you diagnose:

R6XTERRA

^^^^^ You rock. I will give it a look.

Jeff