[Scotty D]

Hi,
This is my first post to this site. Every time I turn on the A/C the radiator fan goes to a high setting. Only when the A/C is on.The car is NOT overheating.
The water pump seems to be working. The A/C refrigerant is at correct pressure. I replaced the coolant temperature sensor. Still does it.
Any suggestions?
Thx

[pbonsalb]

When did it start doing this? The electric fan is triggered by the AC compressor, but I think the fan has 2 settings and don’t think the compressor triggers the high speed setting.

[Scotty D]

Started a couple of weeks ago. Does the cooling fan module affect the fan speed?

[RockCrusher]

Originally Posted by Scotty D

Hi,
This is my first post to this site. Every time I turn on the A/C the radiator fan goes to a high setting. Only when the A/C is on.The car is NOT overheating.
The water pump seems to be working. The A/C refrigerant is at correct pressure. I replaced the coolant temperature sensor. Still does it.
Any suggestions?
Thx

Reads like what it is that controls the radiator fan speeds is wonky. A fail safe mode is the fan runs all the time and the fan is running at its normal speed.

My experience -- with another brand of car -- is the low speed a fan runs at is produced by a ballast resister in the fan wiring harness that causes the fan to run at something less -- a WAG is 1/2 less -- than its normal/full speed.

Then the fan was running full speed all the time I had the car in and the tech confirmed the ballast resister had failed. A new radiator fan wiring harness was the fix. And as fixes went with this car a relatively inexpensive one.

[Scotty D]

Thx.