So the fans check out I also tested the 3 Relays under the fans, check out ok too. Fans will also work if the air conditioner compressor is on. But not under normal driving with Air conditioner off. The car starts to over heat until it is moving then the temp comes down rather quickly. The fan circuit has a problem. So tracing back what’s next? So far I checked the fans, tested OK. Then tested each relay, tested OK. What feeds the primary circuit to the relays?
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1999 Cadillac DeVille Question: Radiator fans do not turn on. 12V feed directly to fan will make the fan operate
Answer #1pushrod December 03, 2012, 18:47Master
Can't beat a GOOD scanner when checking these out!
Answer #2ziptie12 December 03, 2012, 19:48Master
May have multiple sensors/switches for that car. Need to know circuit for fan controls to start. Coolant temp sensor , or rad. fan switch, Some cars have them seperate , others combined . Need to know which you have , then you can test properly.In the meantime--when you come to a stop , turn on the A/C or defrost.
Replycadilaic jack, December 04, 2012, 08:30Rookie
Thank You, I will investigate futher :-)
Answer #3Greg's Orange Auto (11870 Answers) , Orange, CA - (714) 361-9386globalhelper December 04, 2012, 06:16Master
agree with ziptie. get a diag and est so as to not waste time and $