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Old 07-31-2002, 12:15 PM
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jsmith jsmith is offline
Join Date: Aug 2001
Location: At Sea
Posts: 1,729
Question high speed aux fan operation

my cooling system has not really been acting up all summer and has stood up to the heat waves we've been getting here in the east. i do know that the high speed fan kicks in when temps rise and i had been experimenting with different resistors for the cooling mod. today when i pulled off the sensor harness i was surprised that the fan did not kick in. after about 5 seconds in started up and stayed on for about 10 seconds then went off again. i turned on the AC and the fan went on at low speed. all this time temps were at around 90C. i know that the cooling mod works because my temps never go over 100C even with stop and go driving and AC on. when i stop the car after highway driving the temps go up to around 100C and if they are still up when i restart the engine, the high speed fan kicks in - so i know it's working fine.

i always thought that when that thermosensor circuit was open, the computer knew to turn on the fan at high speed. should i be concerned? i waited for a little bit with the thermosensor unplugged and the fan didn't kick in at all after the initial 10 seconds that it went on (the temps were at a steady 90C). the system seems to be doing its job, it's just that this unexpected behavior stumped me...
1993 300e-2.8
- gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
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