larsart

My 92 100cs auxiliary fan turns on high speed when I turn the key on (cold engine) and stays on until I turn the car off. I disconnected the temp sensor driver side lower radiator, no change. Does anyone know which switch/sensor/relay to check (disconnect to see if change in state) and where they are located (physically on the car)?
Thanks so much in advance for the help.

Rusty Spokes

Don't know for sure where the relay is..try this wiring diagram:

I know the low speed fan relay is under the hood in the fusebox. My guess is the high speed fan relay is under the drivers side lower panel, the relays have a paper strip under them indicating what each relay is intended for.

http://12v.org/urs/1997_Audi_A6_Syst...g_Diagrams.pdf

larsart

Hi Rusty Spokes Thanks for your reply. I checked under the drivers side dash and there are relays but not for the high speed fan. I know this because I unplugged each one of them and the fan stays on when key is turned on. I also checked on passenger side by the lower part side panel next to the front door. There are relays there but not for the hspeed relay. I have talked to other Audi mechanics and I have been on a wild goose chase to find the relays/switches/sensors as to their location on this car. I called our local repair and they said they didn't know but would charge 155 dollars and hour to find them. Hard to believe that this would be rocket science.

Rusty Spokes

Got to be a high speed fan relay somewhere..the things that trigger it are the high pressure A/C switch, the control head on the A/C and the thermoswitch in the radiator..as I recall.

I would just investigate further. The relays are grouped together on the drivers side, under the dash or in the fusebox.

Rusty Spokes

http://www.sjmautotechnik.com/troubl...oling.html#fan

Here is a write up on the cooling fan relays..hope the link above helps.