cascadesys

In the summer Texas heat, I find that in traffic my AC compressor will kick off sometimes, and the air coming out of the vents turns lukewarm. It will after a few moments kick back on and the air will return to being cold. I just replaced the compressor with an OEM one about a year ago. It doesn't do this when I am cruising, or when it is not 100+ degrees out.

Thoughts?

alexus6798

iTrader: (24)

Is alternator charging normally? My voltage was fluctuating for a while because I hardly every drive the car, but once I drove it to work for a week straight and now it works as it should.

cascadesys

Alternator is fine

01WS6/tamu

iTrader: (37)

It is either overcharged or the condenser face is obstructed due to road debris dirt oil or paper bag The radiator core and the ac condenser face get filthy with bugs dirt etc physically wash them out with a water hose. Or if your old compressor blew up and they did not replace the condenser bet you 90 to nothing you can pull the orifice tube out even though it is brand new and find that it is loaded with metal and debris from the previous compressor failure. Been doing this tooo many years you can never flush all the crap out of a filthy condenser it's always best to replace them when a compressor pukes majorly. Or last idea are the cooling fans actually switching to high speed.

cascadesys

I replaced the entire system last time the compressor ate it. Including the dryer, orifice tube, condenser, etc. It was charged with a fancy AC machine, input exactly 1.5lbs.

1 FMF

iTrader: (1)

my guess from what you've described is your low on refrigerant.
the smart thing to do would be to put a set of gauges on it and monitor high/low pressures when it happens. when it's 100° outside at idle, if you watch your low side pressure go below 30 psi while high side is over 200 psi then you are low and need to add a few ounces.
when your idling and everything is hot and the ac compressor is pumping, you'll see high side pressure creep higher and higher until the radiator fans kick on high speed then high side pressure will drop and the radiator fans will drop to low speed. if this is happening, then your condenser is clean and working fine. what also tells me it's clean is you say the problem doesn't happen when you're cruising.

01WS6/tamu

iTrader: (37)

Not low on refrigerant shutting off at idle and or high outdoor ambient says shutting down on high pressure.

At idle the suction and head pressure go through the roof in 100+ outdoor ambient.
Also use a amprobe to check both cooling fans and verify they are both working. If one fan motor is dead the dead fan will almost turn as fast as the operating one causing your exact scenario problem. Pulling amp loads verifies each motor is working correctly and they should be pretty close in readings one motor way higher than another means you could have one motor getting weak or one pulling waaay too much and failing when it heats up