AC cutting off

I have a 2002 seville V8 purchased new.

Recently when using the Cruise control set on 70 mph it starts blowing warm air going uphill and cools down going level or downhill AC garage can’t find problem and neither can Dealer. Both say AC working fine but this just started 2 months ago. Help!

I don’t know if the Seville uses vacuum controls for the AC, but if it does, your problem could be a bad check-valve in the vacuum line to the AC controller or a small vacuum leak in or near the controller. If you turn the car off, then turn the key back to on (but don’t start the engine) and let the blower run, does the air all come out the defrost vent?

Are you saying no problem if the cruise is not used? Have you had any type of AC service? I look at a 6 year old car and wonder if the refridgerant charge is correct.You dont mention what the Dealer did to come up with their OK verdict.My WAG is the low pressure switch at or near the accumulator,cheap,no need to deal with the charge if you replace it.

pull the codes through the HVAC,or through the IPC.

then post back.

all caddys have built in diagnostics,no tool needed.