Intermittent HVAC - solved?
06-07-2011, 03:58 AM
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Intermittent HVAC - solved?
I had some intermittent problem with the climate control where it would just go dead occasionally. We discussed it here, and the likeliest suspect was the #17 fuse. My fuse panel is a mess and that fuse melted years ago and was bypassed with a remote fuse, so it seemed reasonable.
I was able to play in the CE panel one day when it died, and found to my surprise that the Window relay (position VI) was the culprit. I pulled it and noted corrosion on the contacts, and it ran hot. I put WD40 on it and plugged it back in, have not had climate control problem for several weeks.
It is odd that I didn't have problems with the windows, and that this relay could affect the complete HVAC circuit.
I bought a new window relay, just in case.
-Sean
I was able to play in the CE panel one day when it died, and found to my surprise that the Window relay (position VI) was the culprit. I pulled it and noted corrosion on the contacts, and it ran hot. I put WD40 on it and plugged it back in, have not had climate control problem for several weeks.
It is odd that I didn't have problems with the windows, and that this relay could affect the complete HVAC circuit.
I bought a new window relay, just in case.
-Sean
08-12-2011, 10:18 PM
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Update: despite my efforts, the climate control head started to die again after a few weeks. So I replaced the window winding relay with a new one, and now it has been fine so far for a number of weeks. Weird circuitry!
-Sean
-Sean
08-12-2011, 11:28 PM
#3
Team Owner
thanks for the update i had a similar issue on an 84 and could never figure it out
08-13-2011, 11:38 AM
#4
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BTW WD40 is not the right product for this - will not really do any good except to lower the insertion forces...
Use an electrical cleaner/deoxidizer/protectant (or nothing - just mechanical cleaning)
Alan
Use an electrical cleaner/deoxidizer/protectant (or nothing - just mechanical cleaning)
Alan
08-14-2011, 11:56 PM
#5
Nordschleife Master
I have a problem with the AC control relay and the headlight switch (see my 'Tricky AC problem'). My AC works perfectly except when you turn the light switch to position 1 or 2. The compressor clutch wire goes from 11.something volt to ZERO. You can hear flap shift and compressor turn of while driving.
You had mentioned window relay interaction with AC function. Any light switch/relay interaction with AC ?
You had mentioned window relay interaction with AC function. Any light switch/relay interaction with AC ?
08-15-2011, 12:03 AM
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Well I can't say for sure about your specific problem, but it is pretty clear that these old relays are prone to internal breakdown that can have very strange effects. You should definitely try to change for new relays and see what happens, the headlight relay is a major thing, mine is running hot right now and may die soon.
-Sean
-Sean
08-15-2011, 01:33 AM
#7
Nordschleife Master
I have a new 928.xxx.xxx.04 relay on the way to replace my 928.xxx.xxx.01 relay. I am still mystified by this interaction. I'm still chopping away at it. I will announce to the Forum with glee when I meet with success.
