430 A/c Blows Hot After 1st Stop

[B-Lawrence]

2001 LS430, Phoenix AZ, 93,000 miles, 1 year since new condenser and charging system (due to damage). The a/c blows ice cold after first start and while driving to work (35 miles). But on occasion if I stop and start a few times in a short period the system blows outside air (moist and hot). If I give the car a rest for an hour or two, the system blows ice cold again. It's acting like some sort of air flow valve is not working right OR it's getting an incorrect signal from the micro processor. Thoughts? Is the car approaching menopause?

[landar]

2001 LS430, Phoenix AZ, 93,000 miles, 1 year since new condenser and charging system (due to damage). The a/c blows ice cold after first start and while driving to work (35 miles). But on occasion if I stop and start a few times in a short period the system blows outside air (moist and hot). If I give the car a rest for an hour or two, the system blows ice cold again. It's acting like some sort of air flow valve is not working right OR it's getting an incorrect signal from the micro processor. Thoughts? Is the car approaching menopause?

Thoughts? I am perplexed as to how the air can be moist in Phoenix?

Well, for starters, I would check to see if the compressor clutch was engaged when it does not work. This is the clutch

which "pulls-in" to make the compressor spin. It makes a distinctive "click" and the engine slows down slightly under the load.

With a helper, try turning the a/c on and off to note the sounds and differences. Forgive me if you already know this. I just dont

want to presume prior experience

When the a/c is not working, you can pull over, open the hood and check. From there, its a crap shoot. If it is engaged, we are looking at

a malfunctioning vent door or similar air routing issue. If it is not engaged, then maybe a bad connection or signal issue.

[SKperformance]

It sounds like there is a vacuum leak causing the a/c system to think the engine is under load .This is causing the a/c to stop blowing because the idle has lowered once hot . Or it may be your low on refrigerant and unless the rpms are high enough it wont pressurize the system.

[B-Lawrence]

It sounds like there is a vacuum leak causing the a/c system to think the engine is under load .This is causing the a/c to stop blowing because the idle has lowered once hot . Or it may be your low on refrigerant and unless the rpms are high enough it wont pressurize the system.

Thanks for the two replies. Here's another bit of data to augment my first post. - The car was off for two hours today then we took off down the freeway. The engine temp gauge was on the second thin white line from the bottom (4 total). I left the a/c off and the engine temp was stable. Then when I turned on the a/c (which got ice cold) the engine temp increased to the top thin white line in less than one minute (very unusual). At this point the a/c kicked off probably due to over heating protection. I have a new radiator and it's full of the correct fluids. Now, here's the kicker. I turn the a/c to AUTO and raise the temp to HOT, the engine temp goes back down to half way in 2 minutes - then if I reduce the temp setting to 75, the a/c goes ice cold until the engine temp goes high again. This cycle repeats and is predictable.

[The Big Bow Wow]

the condensor is infront of the radiator, the condensor takes heat out of the refrigerant, i would check to make sure the condensor fins arent bent and that the condensor is clean

[cardona6569]

Check if your secondary fan is working if it is an electric fan it may need to be replaced or the fan relay may be bad. If the fan is working and your temp is going up I would replace the Thermostat, maybe it is sticking at high temps and the system shuts down to protect itself which can happen the same if it is low or too high on gas. But also do check what the others said also.

CPR