StanUK951

Since I've had my car one thing has really annoyed me - my scratched AC button! I noticed it first time I viewed the car and it was picked up on the PPI. The button worked and even the AC works (or at least it did, this winters project is replacing my AC compressor).

New HVAC units seem to be really expensive and as much as it bothered me, I wasn't about to spend £400+ just to get a better looking switch! Porsche want £120 for a new switch, and I thought that seemed too much too!

I've been keeping an eye out on ebay and spotted a 944 HVAC unit in an auction listing and managed to get it for £40. At first I thought the 944 unit would be a direct swap, but it's a different shape entirely... So, I decided to remove the button and swap it over!

First I removed the button from the 944 unit. Once the surround is unclipped, you have to carefully prise the button itself away from the PCB, breaking the soldered connections. It would have been better if I had used a soldering iron to heat up these joints first, but it seemed to pop off with only a little brute force and you don't need this part of the switch anyway!



This is the old damaged AC button:



This button more easily unclips as it is not soldered to the PCB and has a different back:





The back of the button unclips really easily and can be swapped over with the 964 part.



Once the back parts of the button have been swapped, fitting the 'new' AC button into the 964 HVAC unit is easy.

The finished item installed:

jorijori

Great job Sir! I would go crazy too looking at that button. Interestingly, why AC button? Isn't weather cold most of the time in UK?

StanUK951

Thanks.

No idea why the AC button was damaged. Looks like the decal just delaminated... As you say, I doubt that it was from overuse in the UK, but then AC is also quite good at de-misting windows in our sometimes damp climate!

jorijori

Hi Stan, can you take picture of the back of that unit? My AC works but it blows half of the air downward, I adjusted both levers but no effect, so maybe the control unit itself is bad.

I just want to see how does the lever work, is it mechanically or electronically, TIA.

StanUK951

It's electronic. No mechanical gubbins behind there! I've put it back in the car now so can't really get a photo of the back now. Is your car a 964 though??

jorijori

Yes 964 '93. I'm talking about those two sliders with triangle logo pointing up & down. Okay no problem, thanks.

StanUK951

Ah ok, saw the 3.2 in your avatar and wasn't sure.










These are the best ones I have showing the sliders. As you can see there is a printed circuit board behind them. Hope that helps.

J81 JKR

My unit works well except that the fan has only 1 setting- full! Bit noisy at times, is there an easy fix?

(Sorry to hijack, will start a new thread if need be)

StanUK951

You could try the Tore B site, which has a lot of detail on HVAC problems.

Mine seems to be on all the time! There seems to be no difference between off, or 0, and 1...

jorijori

Thank you Sir for the picture, very appreciated. Brand new one is GBP 400, that is crazy.

wagonface

I need to replace the ac button and the demist/recirc button on the other side on my car - so this is useful. More useful would be if I sent you my unit in the post along with some used fivers, and got a perfect one back...!

Top tip on the 944 unit, the buttons new from Porsche are silly money.

StanUK951

I have a spare de-mist and re-circ button I can let you have very reasonably.....!

Wouldn't fancy replacing your buttons for you, knowing my luck something will go wrong and I'll end up having to fund you a replacement!!!