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Having succesfully completed our first weekend away in the new car I have noticed an intermittent buzzing noise coming from somewhere inside the dashboard.
The noise is fairly quiet and constant and continues after the ignition is turned off and the key removed.
Sounds like it's the little fan on the back of the HVAC unit. Maybe it is just catching on something. Then again, maybe it's just the noise of the fan itself. You should hear it switch off about twenty minutes after turning off the ignition. Unless the engine has been hot enough to run the blower fan after switch off. As you're in Cardiff, the latter is unlikely, I feel.
The fan lives at the back of the unit, directly behind the point arrowed. If you reach to the back of the unit, you can feel its housing mounted on the back of it (about 8 inches back from the vent on the front) and stick your finger in the fan blades.
If it is aggravating enough you may want to remove the top of the dash - it's only a 10 or 15 minute job. Remove the screws from the plastic cover for the windscreen vent, then remove the screws holding the dash top near the windscreen. Take off the black covers at either end of the dash (they're covered when the doors are closed, and just lever off) and remove a screw from each side. Then you have to remove the clock - it should slide out with a bit of work, though some people advocate using a screwdriver with the tip covered in insulating tape to protect the dash. With the clock out you can get to a nut just to its right (on a LHD, presumably the other way round on RHD) and then the whole dash top lifts out. There's lots of space under there - plenty of room for stuff to roll around in!
If you do go in there have a look for the windscreen radio aerial booster wire in the top right hand corner - I'd wondered where it was for ages!
Turn the car off and pull the fuse for the climate control unit (I think #28 but check anyway.) If the buzzing doesn't stop then the problem could be the fuel pump. If the fan behind the CCU doesn't go off after 20 minutes (with the fuse plugged in) it will drain your battery within 2-3 days.
If it doesn't switch off after 20 mins I assume it's replacement time. I will the checks suggested but, worst case scenario does anyone know how much the replacement part costs (and part no would be v helpful)
I've owned my 964 for about 6 weeks now and haven't used it much as I've been really busy. Generally it's been ok but the 'what's that noise' game does get on my neves.
I have a buzzing that happens when the ignition is turned off. Weird thing is it stops when the door is opened. Could this be an issue with the door micro switch? Also another odd one was the passenger mirror motor working constantly. When I played with the joystick it stopped and the interior lights came on (door was open btw)
Yeah I will try the fuse, it's not coming from that location though it sounds high up. I don't know why having the door open or shut effects it as well.
The Climate Control Module (CCU) fan is known for making noises when it gets worn and dirty. I change many of these every year, be sure to be seated when you hear the spare part price from Porsche. The CCU with fan stays on for up to 20 minutes after ignition off.
Cheers,
Tore
02-08-2004, 02:29 PM
Intermittent buzzing dashboard
