AC on 2006 Toyota Avalon works perfectly upon initial start up from sitting for an hour or more. If the outside temps are in the high 80F's or more, it will work intermittently. Air blows out of the vents at all times...just hot, then cold, then hot. If its a very hot day, I can start up the car that morning and drive to work; it will work all the way perfectly. If I stop somewhere on the way, turn off the car, then start it back up 10 mins later, the air will blow hot. I can hear the compressor kick on and off every 2 seconds. Once back on the freeway, it (usually) will start blowing cold air again. But if I'm in town traffic at low speeds or stop/start, it will start blowing hot air again. What would cause it to work normally when its cooler outside but work intermittently when hot?

SOURCE: My heater stopped blowing this morning.

Your heater blower fan unit is in need of replacement.
It's a difficult job so take it to a service center.

Marvin

• 85242 Answers
• Posted on May 11, 2009

SOURCE: AC not blowing cold air at times

poss causes are, sticking low pressure switch, defective Ac compressor clutch closing coil or incorrect clutch driven plate air gap, spec is 0.26 thousands.

SOURCE: 2001 chevy blazer ac problems

freon level is low. add r134 refrigerant and your problem will be solved.

Harvey N Tawatao

• 3854 Answers
• Posted on Jun 10, 2009

SOURCE: Air Conditioner works intermittently

It could be your low pressure cycle switch is going bad. Check the connection to the switch and it's is located on the A/C Accumulator. The other thing to check is the A/C relay and that is located in the glove box. There is a panel in the glove box that say's relay, there is three relays in there and one of the out side relay's out of the three is the A/C. can not remember which one it is. The middle relay is the fuel pump and the other one is the third break light. Switch the two out side relays and see if your A/C get's better. the other thing too is if the R134a is just a little low, and needs to be topped off. Good luck and hope this helps. if your going to try to recharge the A/C system your self, keep in mind not to over charge.

SOURCE: ac compressor does not turn on when car has been sitting & it's hot outside. Works fine in the morning.

either the freon charge is about 1/3 low, or the expansion valve needs to be replaced. Freon is getting into the evaporator, but not in great enough volume to cool the air unless it is coming in cool to start with. check your ac charge, and if it is full, then have it emptied, change out the expansion valve, and recharge it