My fan only runs on high speed so I checked the fan relays in the fuse box. I realized two of them missing. The 2. (radiator fan) and 11. (Relay for fan speed 1) relays. I couldn't find any information on the net what the number for these relays. I have tried many parts stores but they don't know either.
No the fans only run on high speed when the gauge already at the middle.
I checked the cabel of the temp switch. I shorted the pins. First the low speed fan did nothing,then I switched the relay with the AC relay and the fan worked (at least when I shorted the pins). I'm gonna leave it this way now and test it tomorrow. I still don't now if I miss one of the relays in the fusebox or not. There is a place for fan relay (speed 1) at 11. relay under the AC relay. I don't know if that used or not. I couldn't find any info about that.
Thanks .
Dave,
what relay is that? is it in the fusebox numered 214?
Posts: 854
Joined: 3/1/2006 From: Black Mountain, NC Status: offline
there is a bunch of info here http://www.sjmautotechnik.com/trouble_shooting/cooling.html 1 of the fan relays is easy to get to the other is in the vaery far corner ( the very last one i think) and the 214 is on both i also think ... I'll look on mine and get back to you
ahh well that's different ( does the fan stay on all the time ) = fan switch failed and in most cases it an override safety thing and prevents overheating
cskabos, I believe your '93 90 is comparable to my '95 Cabriolet. I also do not have a relay in position #2 and #11, where the fan relays should be. After ALOT of tracing and wiring diagram work, I discovered that these two relays are on the auxiliary relay panel just below the dash behind the lower dash trim panel. There was also a diagram on the inside of the lower dash trim panel explaining what the relays were for, and on what model. i.e. USA model ..... Saudi model ...., etc. The run on relay (2nd speed fan USA model) was in position 17 and the 3rd speed fan relay was in position 18. There was also a 60amp Coolant Fan Fuse located at position B on the aux relay panel. I'm not 100% sure my system works perfectly either. It has to be a hot day for the fans to run without the air conditioning on. I've swapped the relays for ones that I know work. I've also tested the Coolant Fan Control Thermal Switch in the radiator, as you have, and the fans operate. Gauge temp is always OK. Short of draining the radiator and replacing this switch, or being suspicious of the Coolant Fan Control Series Resistance, I won't know for sure about my system. Hope these thoughts help you. Avant, if you can help me too, chime in.
Posts: 854
Joined: 3/1/2006 From: Black Mountain, NC Status: offline
ok guys get a thermoneter ... tape it to the rad near the switch and let the car idle till the fan comes on ... don't turn any ac on or or heat ... lower speed shoud kick in at about 87C and the high speed is at around 93C i belive
Posts: 854
Joined: 3/1/2006 From: Black Mountain, NC Status: offline
does your rad temp switch have 3 or 2 prongs ... 3 prong switches have 3 speeds all togeather (lowest for climate control sys and 2 for engine cooling) ... two prong swithches have 2 speeds (one for climate control sys the other for engine)
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'93 Audi 90s number of fan relays. - 
