j.kenzie@sbcglobal.net

Thanks Tails. I think I get it.

Mads

i have a '89 S4 with dital dash, if the outside temp is working in the dash, it the sensor ok then ?
I get a lot of hot air when i turn the slider i any other potition than cold
Do i have a vaccum porblem ? or is it the inside sensor ?

Mads

jpitman2

If you are seeing correct outside temps on your dash, I would think the outside sensor is OK, and its wiring is OK, as long as the dash gets its signal from the same sensor as the climate controller - if not, start from scratch testing the outside sensor - it and its wiring are the most likely culprits. if you pull the console side off on the pax side, its not too hard to reach the leads to the inside sensor and get a meter on it - I found blowing through the holes was enough to change the resistance here as a test of the sensor. Elsewhere there are notes on which wires you need to find to confirm that side of things (thanks Tails!).
jp 83 Euro S AT 51k

Erling G-P

I have, intermittently, the same symptoms as described by Mrmerlin in the beginning of this thread. Move the slider just one mm to the right of 'full cold', and I get hot air. Occationally though, it seems to work as it's supposed to, although I've never been satisfied with the cooling capacity during summer.

My outside temp display is working, but reading way too low. It shows below-freezing temps in the middle of summer. Would this be indicative of a missing or broken outside temp sensor, and could this trick the HVAC system into providing unnecessary heat ?

Thanks in advance,
Erling

j.kenzie@sbcglobal.net

My understanding is that the temp display sensor is in the side view mirror and the HVAC sensor is under the left front fender. They are independent and could both be misbehaving. Your description sounds like my problem where you are losing contact with your HVAC sensor and having an open circuit (resistance = infinite). If you follow Merlin's advice you should be able to rehab that connector (or eliminate it and solder the wires together as I am going to do, keeping the polarity of the wires preserved).
Good luck

Mads

i think you are right about the outside temp sensor, i found a little black thing sticking out under the mirror. it's only on the driveside.
So i'm going to look at the HVAC sensor
Have you looked at yours Erling ?

Mads

Erling G-P

No, not yet Mads Have a more pressing problem in the form of a fuel leak.

Cheers,
Erling

j.kenzie@sbcglobal.net

Victory!
I got my sensor today (Thanks Jim), soldered it in and now I have my blend flap moving with my temp slider. I can't see it but I can hear the setting motor and some plastic shifting sound inside my heater box. Tomorrow I'll hopefully experience controlled moderation in my HVAV air output.
Thanks to all for the help. It always feels good to fix something you have been putting up with for a while.

bgibby

I had this same problem in my old 86. The sensor in the alt cooling hose was inop, so I used a resistor with a value somewhere in the middle of what the sensor reads & soldered it between the leads. I figured the mild climate here on the Oregon Coast did not call for a sensor designed for outside temps from -20 to 120 & it worked just fine for the 3 years I had the car.

Brian

90GT, Guards Red/Lt Grey Sport Seats, OttX, Bilstein/Eibachs (freshly installed) 73K

j.kenzie@sbcglobal.net

I thought about doing this too.

Mads

Damn, i can't cet my headlight off. how do you do it ?
i can only get the headlight cover, and support bracket off. There is a wire still holding the support, proberbly the hight adjustment.
Is there a write up with some pics. how to remove the headlight ?

Mads

j.kenzie@sbcglobal.net

Remove headlight cover.
Remove two 10mm nuts w/lock washers holding headlight.
Disconnect electrical socket
Pop ball and socket at bottom of headlight.

It took me a while to figure out too.

BTW now I have very comfortable HVAC output.

Alan

Mads - if you mean remoive the headlight to access the temp sensor - thats not how you do it...

Jack/support the car to remove the drivers front wheel. Remove the splash shield & wheel liner to access the hose...

Alan

j.kenzie@sbcglobal.net

Hi Alan,
I got that procedure from Merlin, maybe the first post in this thread. It is much easier than jacking car and removing splash shield. But either way should work.

Alan

Well - I suppose for just a connection issue its OK - I'd think it was rather awkward for reattaching the hose tot the splash shield or installing a whole new sensor...

The headlight yoke is still there in the way right...?

Alan