ac question
 

Hi all, I have a 99 jimmy. I recently replaced the dryer, compressor, and the fixed orrifcie tube for a variable. Before I replaced everything I had the system evacuated and flushed. I did the work and took it back for them to charge the system. I blows nice and cold but just me being over analytical, how cold should it blow? What effect does the outside temp have? I haven't actually put a thermometer next to the vent yet.

It will vary, My 98 Blazer blows ice cold LOW fan @ the vent nearest evap. 32 degrees. But anywhere from that to 42 degrees is OK. Remember sitting idling in hot conditions it will not cool as much. So testing should be done @ about 1500-2000 rpms. Other wise the fan clutch doesn't help with cooling.
I live where the outside temp in the day is 120 degrees my Blazer A/C running down the road will freeze me out of the car.
I hope they evacuated after you replaced all the parts. I hope you did not put in a variable orifice, because you will not be happy at some point. They don't work very well in most cases. Using what GM calls for is the best.

Several things affect register outlet temperature: Condition of the compressor, serpentine belt tensioner, condenser, radiator, engine cooling system, thermostat, fan clutch, ambient temperature, humidity, and correct amount of refrigerant and oil. The clutch cycle switch energizes the compressor clutch at 42psi, (low side) and shuts if off at 22psi. In theory, under optimum conditions, evaporator temperature should average 32 degrees. Register outlet temperature will be slightly higher. The rule of thumb with R134a clutch cycling systems is to expect a 20 degree drop from ambient temperature, if it's more, consider it a bonus.

A VOV will perform far better than a FOT, especially with high ambient temperatures and high underhood temperatures encountered while idling in traffic.

Thanks for the info as always! I did replace the FOT with a VOT based on a lot of positive information I found. I found out if the ever should fail then they just start to operate as a FOT so I wasn't worried. And yes it was evacuated and flushed before I did any work to it.