FredSmith

Thanks for the replies chaps. I've located the heating / ventilation problem thanks to this forum. :-) The Servo in the drivers footwell has seized as the motor seems to have burnt out. I'm in the process of sourcing a new part or fix. The reverse switch is the next thing I'll check, I will have to wait until next weekend though. The reverse lights are not stuck on but do come on as they should when selecting reverse. However, if my memory serves me right (its been a problem for a couple of years) it all started when putting the car in reverse, so it does seem there is a connection to the problem there. Thanks again chaps, I'll update when I get to look at it again. Your help is really appreciated.

FredSmith

In fact the more I think about it, the heater control unit in the dash started to play up as mentioned above after I opened up the console in between the front seats. I needed to get to the handbrake connection and I probably nudged, broke, affected the wiring for the heater control. Its likely the reverse switch is, or possibly the wiring for it is around the same area so I may have shorted the circuit there. H'mm, I'll check all this next weekend. Thanks again :-)

71-3.0-911

Reverse switch is mounted to the transmission. Not likely impacted by console removal.

FredSmith

Ok, thanks. After finding the problem to the heating I'm now inspired to find & fix the control unit issue. I will remove the centre console once more and see if there is anything obvious. I'm not doubting you :-) mainly just doubting me. Ultimately I might change the reverse switch to see if that makes a difference. Thanks again.

ToreB

If the reverse lights work normally, there's nothing wrong with the switch.
Cheers,
Tore

FredSmith

I guess thats a fair point :-) Thanks. I guess its all down to checking all the wiring then, the dash control unit must be shorting out somewhere. I'll check the wiring this weekend. Thanks all.

71-3.0-911

I'm just some random guy on the internet, you don't need to believe me. No worries.

However, if your reverse lights are working as they should, it makes a strong argument that your switch is not the issue.

FredSmith

I believe you and grateful for your steer :-) It makes sense regarding the reverse switch, I was hoping that that would be the problem as it sounds an easier fix than trying to find a wiring problem .... Any other ideas will be gratefully received :-) Thanks again....

Dplus

Thanks Tore and Andy, using your info I was able to diagnose a failed hvac servo motor; fortunately, only the left side motor failed.

Thanks mpruden for this:Rebuilding the mixer servos - Rennlist - Porsche Discussion Forums Great write up and pictures for the removal and replacement. I ended up buying a new servo motor from eeuroparts.com for 274.00, least expensive I could find, rather than try to rebuild.

Best regards,

Darell