Problem with heating and air conditioning. The driver's side is blowing hot air and the passenger side is blowing cold air

SOURCE: automobile air conditioning on max cool, blows hot

I had the same problem when i was working on my 1999 Buick Regal and had to disconnect the battery. I didn't reconnect in the same way that I disconnected the battery from the terminal and noticed that the driver side had no heat or air but the passenger side did. I then disconnected the battery again and reconnected it the same way and now have heat and air on both the driver and passenger side. Hope this helps. Good Luck!

SOURCE: air conditioning

On a w body car with a single temp adjustment control (not a dual zone) your problem should be a low refrigerant charge. Due to the design of this evaporator, a low refrigerant charge will cause the furthest areas from the inlet and outlet hoses (the drivers side) to not remove the heat from the incoming air. This allows the air on the drivers side to be outside temp but refrigerated on the passenger side. In cars with Dual Zone controls you must not only verify the refrigerant charge level, but also check the mode doors which control the air flow and regulate the temp. To check the refrigerant level do not use pressure gauges alone. Verify a proper charge level by checking the temperature of the two aluminum lines going in to the firewall of the vehicle. With the A/C set to high the temperatures should be within 5 degrees of each other. If not, then there is a charge issue. I hope this helps

SOURCE: heat works on driver side, passenger side blows cold air.

Did you check your coolant level or was it low and you added to it at some point? If so the system my need to be bleed or worst case the thermostat is going bad.

SOURCE: heater on blowing cold on driver side and hot on passenger side

This sounds like an air damper is not operating, maybe a cable sticking or a vacuum line come off.

Ronny Bennett Sr.

• 6988 Answers
• Posted on Jul 13, 2010

SOURCE: 1999 pontiac grand prix gtp dual airconditioning

Two things can be the problem,first,try adding ,a little freon,if it is low,it will only cool one side,then if this does not help,there is a door actuator motor that controls this,it could be not working,the dash has to come out to replace this actuator motor,if this was at all helpful,please rate,thank you.