Advice appreciated - yesterday my wife's RX 350 stalled in traffic and wouldn't start. She said that right before it quit, a message came on the Nav screen saying "check AC". With the ignition in the on position I turned off the AC and the car started. Car runs fine with AC off. AC on, no go. Any ideas? Thanks in advance

 

Sounds like the a/c compressor has taken a dump...

at least that is first instinct given her symptoms...

can you turn the car on, then turn the a/c on and it kills the car? if it doesn't, does the a/c blow cold?

One other thing you can do - locate the a/c compressor and see if you can turn it - you won't be able to turn the whole thing, as the belt will be there, but, the compressor clutch will not be engaged with the car off - how hard is it to turn the compressor? it should be somewhat tough, but very doable, probably with just your hand, if you can get to it...

if this isn't the issue, we may have an idle air / throttle sensor issue...

 

Thanks for the fast response. I'll check it out.