Elec Fan not running

**00_transam_vert** · 09-12-2007, 12:45 PM

My Fan on my 00 T/A Convert. will not run without the A/C on. It runs with the A/C on to cool the condensor. My initial thought would be a temp sensor. I've also tested all 3 fan relay and they're all good...any thoughts?

**2001NBMZ28** · 09-12-2007, 04:08 PM

Welcome to the board

. The stock fan settings are set pretty high. Both fans should run on either low or high speeds simultaneously when commanded on. If only one comes on something's wrong. The car isn't overheating/gauge normal with the AC off?

**Hot Black Trans-Am** · 09-12-2007, 04:23 PM

Only one fan runs unless the air is on or the car is over a certain temp.

**LS2Tuner** · 09-12-2007, 05:01 PM

Originally Posted by 00_transam_vert

My Fan on my 00 T/A Convert. will not run without the A/C on. It runs with the A/C on to cool the condensor. My initial thought would be a temp sensor. I've also tested all 3 fan relay and they're all good...any thoughts?

Welcome....
Is the temp getting high?
Being a 2000 that temp. sensor is a cheap replacement anyways just to have piece of mind.

**00_transam_vert** · 09-12-2007, 06:05 PM

The car doesn't run much higher than normal. Maybe 190-200, I should have been more specific in my description, neither fan will ran at all without the A/C on. If i forget (and i have) it WILL boil the a/f. Where is the temp sender located for the fans..i know sending unit for the gauge is on the head but there is anouther for the fans! Thanks for the quick replys guys!

**2001NBMZ28** · 09-13-2007, 11:19 AM

The LT1's had two sensors, one for the gauge and one for the PCM. Yours just has one in the drivers side head for both.

**00_transam_vert** · 09-13-2007, 05:01 PM

If this is true, than there is nothing wrong with the temp sending unit, gauge has always been accurate! There's gotta be somting b/w the Relay's and the fan then! Does anyone have a wiring diagram or where to find one?

**2001NBMZ28** · 09-13-2007, 05:27 PM

The '99 and up gauges are not accurate, last year they were accurate was in '98 and had a 3 wire ECT sensor. Plus if it was the sensor I'd think you'd get an ECT code. Stock fan settings are really high, do you know someone with a scanner that can read the actual temps? I disagree with the earlier post about only one fan coming on - in late '94 and into '95 GM went to the 3 relay system and both come on either low or high speed. Just under 210 is normal on my gauge but that's F, when you say 190-200 is that C, maybe export gauges are different?