What's the matter with my AC?

[David Pendleton]

Hello all.



My AC blows cold (very cold) for about 5 minutes, then warm and damp for five minutes, then cold again.



This ain't normal, I know. Any ideas before I bring it in?



Thanks all.



Dave

 

[rbattelle]

Sounds like the evaporator is freezing up. Improper refrigerant charge will do this.

 

[B.G. Smith]

Ac

I would guess from the color of your truck in your signature that it is an 03? The temperature of the AC when everything is working correctly is determined by the clutch cycling switch screwed into the side of the accumulator and is controlled by the blend air door in the system by allowing warm air from the heater core to mix with the cooled air. Usually when a system is freezing up it won't thaw out till the AC is turned off for a while. Sounds like the clutch cycling switch may be malfunctioning. To check, turn the AC on and watch the compressor clutch, it should stay engaged while idling when the outside temp. is in the upper 80/90 degs. If it runs for the "5 minutes" then cuts off and stays off for "5 minutes" the switch is probably bad. bg

 

[CClements]

I have the same problem. I asked about it last time I was at the dealership but got no answers. From searching here I read about a



Fin Temp sensor

bad orifice Wich one do I tell them is causing the problem?

3 psi overcharge

bad check valve



Does anyone have a deffinitive answer on the 03 ac freez up problem?

 

[txhawg]

Fin Temp sensor

bad orifice Wich one do I tell them is causing the problem?

3 psi overcharge

bad check valve



Does anyone have a deffinitive answer on the 03 ac freez up problem?

My ex-wife had a bad orifice, and her check valve was definitely malfunctioning. But both of these made her very frigid, so I don't think they are the problem. Complaining about it did no good, so I traded her in for a new wife. :-laf

 

[zues]

I was at the dealer and had my ECM re-flashed and one of the flashes is for A/C problems.