04 LS radiator fan no high speed

[trk pny]

My wife's 04 LS v6 is having Ac cooling issues. It seems that the electric radiator cooling fan is only working at low speed. We turn the AC on max and the underhood fan comes in but not at high speed. Anyone know of a speed control or solenoid that I should check? Any way to test fan for high speed operation? Thanks

 

[joegr]

If high side refrigerant pressure is not high, then the fan does not turn very fast. The pressure is a measure of how much heat needed to be removed from the condenser. Low pressure = low heat = no reason for high fan.

The issue could be low refrigerant charge (due to a leak that needs to be identified and fixed), or it could be due to a bad compressor (scroll control valve usually).

 

[trk pny]

joegr. thanks for the info. it looks to be as you wrote.
low charge did not call for high speed fan. added some 134a and the system seems to have picked up