dukmon

Unit if working fine so far a operation, heating and cooling. A buzzing noise that is kind of loud began yesterday. It buzzes nonstop, only slightly reducing in tone when accelerating or if using the air conditioning (pressing either AC button.) It continues to buzz even when the ignition is turned off during the brief period afterwards during which stereo remains on.

I probably did a horrible job describing what's going on.



Any idea what the issue may be?

JohnK964

dukmon

Hey John. It's sort of a transistor radio buzzing sort of sound..... Is there a chance that fan would come on even while the unit isn't being used? It's nice spring weather here, so I haven't had the need to use the unit at all, lately. It was while trying to track down the noise culprit that I realized pressing the AC buttons stopped the buzzing.

JohnK964

ToreB

This sounds like the internal CCU power relay is buzzing for some reason. It may be a problem with the power supply, (check fuse 1 for any burn marks or intermittent contact) or an internal electronic problem in the unit. Both these causes are known culprits.
It could also be the CCU fan at the back of the unit that is giving up the ghost, this can rattle a lot when it wears out. This small fan is imperative for measuring the cabin temperature.
The Climate Control Unit is important for controlling engine cooling such as the oil cooler and rear fans, so you should have this checked before putting a hgigh load on the engine, at least keep an eye on the engine temperature.
Cheers,
Tore

dukmon

Good info fellas. Thanks!

I have a video I'll try to post.

dukmon

Short video.......

ToreB

Typical CCU fan whirr. Try to stop the fan by sticking your finger into the fan propeller, it is reachable from under the dashboard. You could also try to give the fan housing a nudge to make it more silent.
A new fan costs about USD 400 from Porsche.
Cheers,
Tore