My low and high fan speed pressure sensors in the condensor are faulty, they run all the time, with the AC off, when the car is cold in the morning. thats ,must be why I found them unplugged. Until I can replace them I tapped into the compressor signal line with the coil of a relay. The coil draws 225 mA I then ran the wires for the low speed pressrue sw through the normally open contacts of the relay. Now the fan is on whenever the copressor is on OR whenever the radiator temp switch says it time. Will the small current draw of the coil have any effect on the existing circuitry. Will having the fan on on the highway bring diminishing returns in terms of cooling efficiency.


thanks,

Matt

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'82 240 - 144k; '87 760T 133k

Hey you can get those sensors on EBay cheap. $30
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1854411063
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1996 964 128,000

i think I got ya beat, brian @ usedvolvoparts.com is selling them to me for 5 bucks ea. I hope they work!!!!


M
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'82 240 - 144k; '87 760T 133k

Should be OK. All you will do is wear out the fan motor a little more quickly and there might be a reduction in fuel economy. The obvious solution is to replace the sensors.

I hate to turn my car into frankenstein, but I could tap into the OD circuit to cut out the fan when the OD is engaged.... Or is this more trouble than its worth??

Matt

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'82 240 - 144k; '87 760T 133k

I don't know if you want to poke around that circuit too much....remember these cars have a finicky overdrive solinoid to begin with and i dont know what tapping into that circuit could do to it.