I drove a ‘98 LS out to Vegas from Chicago for a family member back in 2012 and I fell in love with the car after not liking it when my relative bough it certified used in 2000. On the way to Vegas, I noticed that A/C kept kicking on and off when the car was standing still, but was very cold when moving and almost hot when not moving, again the compressor would cut on and off. I took it to Lexus of Las Vegas which first replaced the alternator and then on another return visit the air compressor. I hadn’t driven it again until today July 15, 2021 because he offered to give me the car. It still gets warm with the A/C on when stopped and cold when moving with the compressor cutting on and off when stopped at a light for instance. He’s only put 3000 miles on it since it arrived in Vegas and the compressor was installed new in 2012 and the same problem persists. Any clues guys?

 

Radiator fans not working? Does the car have a low idle?

 

Idling around 500 rpm. I thought I heard the cooling fan come on, but I'll have to check and see.

 

Car has a primary thermo-mechanical clutch for the radiator, and a 2ndary electric cooling fan that kicks on for the air conditioning.

When was the last time the serpentine\drive belt was replaced? And how doe the pullies look. That would be my first thing to look at if the air conditioning is tied to whether the car is moving or not.

Also am I reading your post right, he only put 3000 miles in 9 years on the car? That's quite a lot of sitting around - and cars don't like to sit. Weird stuff happens when they do. Rubbers and oils degrade.

The car should idle at ~750 rpm in neutral, a bit lower in gear.

 

He only comes out about 5 times a year, so it sits a lot. I'll take a look at the idle and pulleys and the belts.