I'm a senior woman with a 2000 Pontiac Bonneville that I love however the heat only works for the driver'* side and the passenger freezes with cold air at his/her feet and above the glove compartment vents. Any suggestions? I hesitate to visit dealership without some insight as to what'* going on. Would greatly appreciate any help.

I believe there are mix actuators that move to open and close different vents and the hot cold sides. Have them check the air mix actuators.

Thanks, Dan. I'm glad to have something to say when I take it in to be fixed. Would you have any idea what they'd have to do to check and repair if a problem? I really appreciate your help, Dan...and your quick response to my posting.

I'm not the most knowledgeable with your year, I'm more 96-99 but is should be similar. If yours is the same there should be a ccess door in the glove box and you can see the air mix actuator threw that door. You will want to see if the actuator move.

Many thanks, Dan. Have a wonderful and healthy New Year!

Same to you, and good luck.

Let me add to danthurs' answer that there is an actuators. If it'* a dual system with separate controls for the passenger side, then it has a separate actuator. The actuator is small electric motor unit that moves a vane inside the heater box to make more or less air from the heater path mix with air that bypasses the heater core. The motors burn out or the gears break.

The actuators are visible from under the dash. There are thin plastic shields or hush panels that come off with a couple of screws on the passenger side (and driver'* side). Then a mechanic can watch the actuators move their arm which is connected to the vanes inside the box. If they can visually see that an actuator is not move when the heater controls are changed then replacement is the probably solution.

This does not have to be at a dealer. A good mechanic who does this kind of interior work rather than mostly motor and brakes, etc., can do it and should be much cheaper. Even a talented backyard mechanic can change an actuator after they determine one is the problem; some parts are put in and designed to be quick changes anymore around the heater system.

The advantage to a dealer is they will diagnose it and replace it and probably get it right the first time if there is another cause.

Actuators have been failing occasionally on Buicks and Bonnevilles since they went electric controls instead of vacuum in 2000. So actuator is usually the first place to start.

Thanks. I'm in awe with the expertise on this site. I feel as though I've walked through a door and found a huge treasure.

Just wanted to mention I took my car to a dealer in Lakewood NJ to be fixed and it was as you guys suggested the actuator on the passenger side. I was unhappy as initially I was led to believe by the service department when I called that it would cost $200 to fix the actuator and in the end it came to near $500 and he tells me I also have a problem with the actuator on the left (driver side) not blowing out "cold" air. I'm having only the passenger side taken care of by them as I am distrustful. Billboost37 will be fixing my fuel sender and I'll pass this new problem by him when I see him at that time and see what he thinks.

Forgot to mention that I first took my car to a mechanic but although he had my car for the whole day, he could only identify that it was the actuator and would get back to me with the cost, etc. He never did so that'* why I finally went to the Pontiac dealer in my area. I only wish I could find a good Pontiac mechanic in NJ.