Rad Fans Not Running

[JPGTP]

1995 Grand Prix GTP (3.4l DOHC)

I am in a bit of a pickle. Yesterday I replaced my water pump to solve a coolant leak issue, and have now noticed that the rad fans are not coming on.

The car runs consistently over the 100 degree Celsius mark (according to the dash gauge). I check both the fan relays and they are fine, fuses check out ok, and if I hard wire the fans they spin like mad. Also, the thermostat is functioning appropriately.

From what I have read, it could be a coolant (temp) sensor issue, but based on the schematics I have, there is only one temp sensor...but then I don't see how the gauge would be working and the signal to the PCM not be? Are there actually 2 sensors, and can anyone tell me where the two are? JP

[JPGTP]

I think I found one of the sensors by the EGR pipe....I disconnected it (to simulate infinte resistance = high coolant temp) and the primary fan came on right away. This is leading me to think this is the sensor to replace. Any thoughts on if I am on the right track with this? JP

[JPGTP]

I have replaced both temperature sensors and the thermostat. I the car is left to idle the temperature (according to the interior gauge) hits about 112 C. The main fan comes on at a bit past the 112 mark and brings it to about 106 and the process repeats.

I am truly stumped now. The rad is getting uniformly hot, and there is a mix of 50\50 prestone. Could this come down to a bad gauge on the console??

[SappySE107]

The gauge likely isn't correct like you would think (i know half way between 2 points is not really half way). A scan tool will tell you the temp the engine sees. With new stat and sensor, its most likely the way its programmed and nothing is wrong.