Thread: aux fan 300SL
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Old 05-15-2002, 03:28 PM
Arthur Dalton Arthur Dalton is offline
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Join Date: Aug 1999
Location: Florida / N.H.
Posts: 8,768
OK .. You may have misread the resistor..
[ when trying to explain some of these wiring problems, I always assume one knows how to set up a meter or knows to disconnect one side , etc. cuz we do this on "auto-pilot" , so to speak... but then I reread my post after it goes out and I say , "Damn, I should have mentioned XYZ. Is this guy giving me backfeed values????].

Anyway, the best test for the high speed is to get a 150-180 ,
ohm , 1/4 watt resistor and bridge the CTS harness plug.
Sometimes the removal works and sometimes it does not... I think it has to do with how close to cut-in ohm spec it is when trying this method .[ maybe SB or Doc knows that one]

But I have found the resistor bridge circuit to work , as the ecu now reads beyound the cut-in temp/ohms
Another is to get the temp/resistance chart and read the CTS with your meter using the temp gauge as reference.

Be aware that there are 2 relays . one for low fan/resistor, and one for the high coolant temp sender circuit....
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