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Pontiac Bonneville Heating/Cooling Problems



  • bonne03bonne03 Posts: 3
    I have an 03 Bonneville SLE with a strange quirk. It has the Dual Climate Control with Digital Readout. In the past month or so when I start the car it will light up and appear to be working however no air is coming out the vents. The settings can't be changed (changing to defrost vs. auto etc) .. after a period of time driving down the road (sometimes up to 20 minutes) then it will begin to function normally and then does work fine. I did replace the control unit itself but that hasn't fixed the problem. When it does work all settings can be changed, air blows as it should etc. it will work perfectly .. however the long delays are beyond a nusiance and I'm worried this winter about not having defrost (of course having a/c right now would be nice also)

    Has anyone else had this problem, any ideas how to fix?
  • I have a 2005 Bonneville. It isn't an SE or anything special. It has been running great until recently. Most of the time when I start the it the heater blows, but sometimes it doesn't. Sometimes when it doesn't start upon initiation, it will eventually come on, other times it just doesn't come on at all. The next time I start the car, it will be working. My original thought was to replace the relay, however when I looked in the fuse box there isn't a relay for the HVAC Solenoid, so I don't know what else to do. I don't have any warning lights on and when the blower is working the heat is great.

    Any suggestions?
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    >It isn't an SE or anything special.

    If it's a Bonneville, it's already special!

    >Most of the time when I start the it the heater blows, but sometimes it doesn't.

    I suspect the control on the dash was not the problem.

    One most likely point is the blower motor itself. Some are having wear on the commutator so that when it stops it may not be making electrical contact. Then when the dash control and the programmer on the heater box say blow, the blower motor doesn't move. When the car hits a bump, or something vibrates the motor, the commutator makes contact and the blower starts working while you're driving.

    Next time your start the car and turning the blower speed up doesn't result in any air movement, use the toe of your foot on the right side of the hump and tap upward against the blower housing; keep your foot back toward the firewall. Most likely the blower will come on. Keep the key on while you do this.

    The snap connector in that area may have a burned contact--check it first by disconnecting and looking for burning or melted plastic.

    There also is a blower control module if you have the automatic control AC unit (C69). These are next to the blower and control the speed using a power transistor.

    The blower can be replaced easily by removing the plastic panel under the bottom of the dash with a few screws and clips. The blower motor is held in with 3 screws and wiggles out with the squirrel cage attached. Some people say to pull the carpet back from the firewall to allow another inch of room and that will make it easier to wiggle in and out.

    This requires working lying on the floor and across the seats, but several types of blowers are available on the net. Some are much better quality than others. I'd suggest to look at some of the choices. Click through their online parts list to get to heating and cooling and then to blower motor.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • vike2vike2 Posts: 4
    This all started when the battery was changed, with no keys in the ignition. ac heater monitor in the dash started blinking the temp and then goes to out side air temp, which does not blink. no hot heat, just warm. unhooked the battery cables tied them together to drain the system, had 4 volts to 0 volts. did not reset the system. programmer moving duct doors correctly, acutator has a hard spot in it and hangs up, (new one on order), when moving rod. can move the rod manually thru access hole in the glove box, get cold and hot air to work properly then. but temp still blinks on dash monitor. any ideas how to correct monitor temp blinking, changed the monitor from one car to another and still blinked. lost and need ideas.
  • I have a 1993 Bonneville SSE. A few weeks ago I changed the battery and the same thing happened to me. I have not figured out the perfect solution, however this has been working for me. Set the temp on the lowest setting which is 60 and on AUTO. Mine blinks for about 20-30 seconds and then stops. When the blinking stops then you can put the heat up to whatever temp you want and it will work fine. If you start on any other temp besides the lowest the digital readout won't stop blinking and you won't have heat.... What stinks is everytime you turn the car off you will have to perform this procedure. Hope this helps! Let me know if you find the right fix...
  • vike2vike2 Posts: 4
    that helps. does any one know how to put in a new acuator with out taking the dash out? does anyone know if you change the acuator if that will make the blinking stop on the temp? does anyone have a diagram of how to take the dash apart?
  • m20cm20c Posts: 4
    No matter where the digital temp is set to, 60 -- 90, AC on or off, heat comes out the vents. AC compressor is not cycling, check freon .. OK, so I know it is not low. When temp set to 60, no matter what mode it is in, defrost, at feet or center vents, heat comes out. Could it be the heat divertor? And if so, is it located behind the glove box? What steps do I need to go through to get access to it?
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    Do you have a manual system or the dual control system.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • m20cm20c Posts: 4
    I do not have dual control. Electronic digital control of AC and Heat.
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    Yours may look like this...

    At the middle left of the picture is a white arm with a thin threaded rod that goes to the right about 5 inches to a little white plastic arm that is part of an actuator.

    By taking off the hush panel under the dash (3 screws and two taps at the firewall) and maybe taking off the glovebox door, you can see that arm. By moving it while the key and heater are on, you should see it go right and left to change the blend door to give the temp you want. It may be unsnapped from the arm. It just snaps on sideways and you would have the door at the left inside the heater on full heat and the digital temp control at full heat request (90) and then snap on then.

    This picture may help more. These have had the dash removed for some kind of work. Yours can still be reached but will not be this easy, depending on the year.

    The actuator may be burned out or the gears cracked. They are available at or You'll need to be very careful you get the right one for your car. IF it is bad, you can take the actuator off with two screws-not easy to get at one, and check the part number on it. Put that part number into the blank on gmpartsdirect or rockauto and it will give you the right replacement.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • m20cm20c Posts: 4
    Thanks for you help!!! I'll dig into it and let you know how I make out.
  • m20cm20c Posts: 4
    Thanks for the help, the actuator was stuck mid position, just freed it up and started working again.
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    Great. Thanks for reporting back.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • vike2vike2 Posts: 4
    thanks everyone. this will be my last post. unfortunately my 1995 bonneville had a front end collision, it was totaled. i am sad but no one was hurt thank god for that. i loved my car and am very sad about this thank you all.
    vike 2
  • vike2vike2 Posts: 4
    I will keep checking in on this site once in a while to see if I can help with anything.
    vike2. thanks again.
  • I have a 2000 Bonnie SE, the passenger side blows super cold air without any problem. However the driver dash side only blows hot, with just a barely noticeable smidgeon of cool if at all.
    It's a dual zone electronic with digital readout, the rear passenger outlet is also warm.
    Air flow seems to switch areas selected without any problem. about 3 months ago, autozone guy, put in some freon in one of the 2 lines that run parallel to each other alongside the fender wall, it seemed to help. just a tiny bit, nothing to be elated about.
    Asking the passenger side outlet to cool the whole interior, just won't do it, and pointing the outlets toward the driver for some relief, won't do it either.

    Bottom line--Drivers side does not cool- (Nor do the middle ones on dash).

    PLEASE HELP, can't afford a mechanic and need to drive to LA to visit with my son who is on his 4th tour to Iraq with the Marine Corps, the interior gets very hot for my wife and we must drive during the day from Arizona .

    I anyone can tell me how to tackle this problem, we'll be forever grateful.

    If some one can tell me where to look and how to get to it. I have no problem tackling it.

  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    Most 2000+ cars with this problem find their refrigerant charge is low. Because of the flow of coolant into the evaporator coil, the side that gets the coolant first is the area of the coil over which the airflow to the passenger side passes. So that air gets cooled while the warmer side of the evaporator doesn't cool the air going to the driver.

    If you have some expertise, you can get a 134a can with a gauge at Walmart or other store. Do not get the ones with sealer, dye, superfreon, in them. I bought a separate gauge they had and just buy the plain cans. Recharge with the motor running and the heater fan blowing on high to the pressure they indicate on the gauge.

    You'll probably find your cooling is back.

    If there's an actuator problem inside the car that moves the vanes that control the air, that too can be changed by a fairly knowledgeable home tech type. If when mornings are cold and you have the heater on, both sides can heat and adjust with heating occuring, you probably just have low refrigerant. If the actuator is slipping, you may have trouble with heating settings.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • Thank you very much for your prompt response, I will get these items and hope is just a coolant issue.

    IF is an actuator problem (hope not) how difficult is it to remove the dashboard to get to the actuator ?? and if damaged is it possible to leave it in a permanent "cooling position" ?

    We wont see winter here until about January
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    The actuators are even easier to access than they used to be.

    Remove the hush panel and be sure it's the actuator that won't work by watching as the settings on the dash are changed with the key ON. A couple of screws and the new actuator slips on. Of course there's an electrical connector. I can supply a graphic if it comes down to that. But I'd bet your actuator is adjusting the heat temps for you, indicating it's okay and the problem is in the low charge. But the actuators do have a failure rate.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • THANK YOU SO MUCH!!!!!!!!!!!!!, I happened to drive by a service shop and decided to stop and inquire about the cost for 'topping off" the freon. Just as you said, Freon was way low, charged me $45.00 and problem solved, I figured I may have spent this much at least if I had tried to do it myself.
    Now I have to watch how cold I keep it, so my face doesn't freeze off : )
    I want to Thank Imidazol97 for his quick and very effective help !!!!!!!!!!!!!!!!!!as well as the people who put this website together.
    God bless You guys !!!!!!!!!!!!!!!!!!!!!!!!!!!!
    I am on my way to California this friday.
    Thanks again :)
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    thanks for coming back to let us know what worked.

    Actually a can of freon may be a few dollars and 10$ or so for a gauge that's reusable. Doing a quick connect to the low pressure side with the motor and system running on a 70 deg day, and you turn on the freon in the can let is slowly recharge the system until the pressure gauge gets the needle to the top of the green section. Then quickly turn off the feed, remove the screw on connection, replace the plastic cap to keep the connector clean and you're done.

    But it does require some experience with working on the car and some confidence. That varies with the person's past at working on cars.

    If I needed air tomorrow, and if I wasn't certain about what to do, $45 would be a bargain. I'd say that shop deserves your business the next time you have car trouble. They didn't rip you off.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • muscle1970muscle1970 Posts: 1
    Hi...I have a 2005 Bonneville, and it is doing the same thing. There has been a lot of mention of the accuator, and some say that you can access it through one of the vents. Have you had any luck at repairing this problem? I, like you, cannot afford the expensive repairs. Especially if there is an easy way to fix it myself. The dealer estimated that it would take 8 hours labor.
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    Is it a dual zone system with different temps for driver and passenger?

    But first check the coolant charge. That seems to be the most common problem: loss of freon charge. It still cools, but not as well. And the cool part of the evaporate is where the air to the passenger goes through.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • I have a very strange problem happening with my 1996 Bonneville SE.

    Example: I start my car, turn on the A/C it blows cold air. However, when I shut my car off and wait just about a minute and then turn it back on it blows hot air. Then if I shut it off again and wait a minute restart it then it blows cold air again. I've tried this over and over and it is consistent everytime. What ever temp it was blowing at the time I shut off the car the next time it will blow the opposite temperature.

    Plus it takes about a minute for it to cut over each time I start the car up.

    Also when I turn on the blower it seems to always just blow air at my feet even though I've got it set to blow through the vents, but after about 4 to 5 minutes it starts to slowly blow through the vents and then increases to normal air volume.

    Has anybody ever had the same problems and if so how did you fix them? Photos would be greatly appreciated.
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    You are going to have to diagnose what's wrong.

    >Also when I turn on the blower it seems to always just blow air at my feet even though I've got it set to blow through the vents,

    If you have automatic temp control AC,

    If that's what's making it hot, you're in luck. But check to see if there's cold air coming out the defrost. If you're in a hot climate you won't feel any cold from it at all, but the cooler is still working under the hood.

    If the air is coming out the defrost and heater, you have lost vacuum to the interior. Since the vacuum returns!!!! after a few minutes, check the vacuum liine under the hood. On your 1996 I believe that starts at a little slick plastic tube (1/4 inch) that comes out of the upper intake manifold right next to the big black rubber hose going to the brake booster diaphragm.

    Follow that line. Feel the ends. Feel for cracks. It goes to a one-way valve over on the passenger side near the dryer unit for the AC and then there's a branch at a T. One goes to the storage tank under the fender in front of the right wheel. Check that tank for cracks losing vacuum and check the connection.

    Check all lines on the motor for cracks and leaks due to age or rot. They may be affecting your vacuum.

    The other branch of the T goes to the inside.

    Run motor and then pull of the connection at the reservoir under the fender to see if there's a big whoosh as air goes in to replace the vacuum.

    Otherwise check under the passenger dash. Remove the hush panel. Remove the door for the glovebox. Check for vacuum there at the violet line connection to the black line coming through the dash from the engine compartment.

    Problem may be same as here.
    Use 1/8 inch internal diameter rubber gas hose to connect the lines to bypass the clear plastic connector that sucks shut after it softens. Pieces about 1.5 inch or less work fine.

    You also might have a vacuum actuator for one of the doors in the heater box that has cracked or torn. When you move the control setting to differnet places, feel each of the 4 vacuum actuators over above the driver's foot to see if they move fully. The back of the vacuum motor is open and you can use a finger to follow its movement or even to push and make each one operate. I believe the blue tube goes to the one that closes the door above the dash vents and makes the air come out the dash vents instead of the defrost vents.

    On the other hand:

    >However, when I shut my car off and wait just about a minute and then turn it back on it blows hot air. Then if I shut it off again and wait a minute restart it then it blows cold air again. I've tried this over and over and it is consistent everytime

    If when the car is started and there's no AC, have the hood open and check to see if the AC compressor is turning. Check to see if the metal AC line is getting cold like it usually does. That would indicate a relay or something might not be turning on. There's a relay in the relay center for the AC compressor clutch. But if contacts burned on it, I don't think it would be as definite in reconnecting like you're describing.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • jd0754jd0754 Posts: 3
    I have a 1998 Bonneville air will not come out of the center vents,but from the defrost and floor vents. After sometime it will eventually start coming out the center but will also continue out of defrost and floor. If you turn the fan speed down manually you can here a clicking sound like one of the doors are closing. The longer the clicking goes the more air comes out of the center vents. Just recently had an actuator replaced because we were getting no air from the center at all. Any ideas?
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    The actuator for the center vents is vacuum operated. It's just like on my leSabre. It has a blue tube going to it. Check for vacuum in that blue tube... when the AC is requested from the programmer via the dash control panel.

    Also..., does your car have dual temperature controls? I am not clear from my service manual if a separate temp control is available for the passenger.

    The one way to check the vacuum actuator for the AC doors is to use a vacuum line from the heater or recirculate vacuum motors with the control panel requesting floor heat or recirculate. Snap the hose onto the AC vacuum motor and see if it works. Be aware you can feel the backside of the actuators which is open and feel the diaphragm move when vacuum is applied. That helps eliminate a tear or leak in the actuator itself. These actuators are above the driver's right foot. The is one with two leads to it for the floor doors-they close partly when doing windshield/floor-so there's a tube to both sides of the actuator for that one. There's an actuator that rotates high up in the HVAC box to close off flow to the defroster. That makes air coming up go out the dash vents. The heater opening at the floor closes off to make the air go up to the defrost or to the AC dash vents. The other motor is to the left and on the air return for inside air; it draws air from above the driver's feet and uses that rather than all outside air. Be aware that hose has a restrictor in it to open and close slowly; the restrictor is a ceramic that bleeds air through to control how quickly the opening occurs.

    If you take off the passenger hush panel and remove the glovebox door, you'll be able to see the electric actuator which moves the temperature door inside the HVAC box. That actuator may be inside the programmer box or may be a separate one up on top. By watching it while moving the temperature so it has to adjust, you can see if the clicking is coming from the actuator.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • Have a 2002 Bonneville with the dual zone system, and it is ONLY the driver's side that is blowing warm air, but even that is mostly when the car is up at speed.

    Passenger side blows cold all the time.

    Driver's side will blow cold when the car is sitting still or when moving a neighborhood speeds, but as you go up to highway, the air gets warmer (though never is fully outside air temp).

    Driver's side will blow hot when you ask it to with controls and definitely cools down a little when you turn the A/C on, but is probably 15-20 degrees warmer than the passenger side.

    Any thoughts?
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 22,054
    The larger number of problems is that the R134a is low on charge. The freon enters the evaporator in the area that the air to the passenger flows over, so it gets the colder metal as the freon expand and cools. The freon doesn't make it to the other side where the driver's air is moving over the coils.

    First thing is to check on freon charge.

    The other is that some have trouble with actuators. I believe there are three and they are all on the driver's side of the HVAC stack in the middle of the car.

    Take off the hush panel, and move the AC controls to different settings and you should be able to cause each of those to move. You can see the axle of the actuator move people say. They are also made for easy remove and replace. Just be careful to install correctly. Some actuators have failed, but I would think that would cause you to have the wrong temperature all the time.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • jd0754jd0754 Posts: 3
    This thing is all balled up, does not have dual temp control, put selector on floor setting and it comes out of both the floor and defrost all the time, put on defrost setting and it does the same, put on center vent and eventually it will come out of the center vents, temp seems to be ok I had it at 60 and it was cold, it's just that it won't come out of the right vents.
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