VicSWFL

Greetings:

I have a gently used 2003 Lexus es300 with 170k miles. While recently adding some refrigerant to the air conditioning I noticed that only the passenger side cooling fan was running. This was shortly after a cold start and with the air conditioning on COLD with the interior fan on high. Should both fans be running in this situation?

Thanks,

Vic
Fort Myers, Florida

Arsenii

Hello,

The passenger side fan is a supplemental one, specifically designed to run when A/C is on to cool the refrigerant down before it enters the evaporator. The Main fan on the Driver's side, on the other hand, is designed to cool the engine down after it reaches the operating temperature, or when there is a catastrophic failure in the A/C system, like an overpressure or a bad pressure switch.

In short, wait until the car would reach operating temperature and see if the Main fan would kick in, if not, the engine temperature at idle will start to go up, which will be a clear indication that there is a fault in the system.

Hope this helps and best of luck!

VicSWFL

Thank you for your knowledge Arsenii. Mystery solved.