Edmunds dealer partner, Bayway Leasing, is now offering transparent lease deals via these forums. Click here to see the latest vehicles!

Pontiac Bonneville Heating/Cooling Problems

1235»

Comments

  • santonio03santonio03 Member Posts: 7
    Clean Evap core, replace Blower and resistor. All the settings work(from defrost to vents to floor)
  • phr04phr04 Member Posts: 1
    The instructions for replacing this motor seem to indicate that it can be reached by removing the instrument panel cluster. I have done that and am still a long way from even being able to see the actuator. It appears that the entire dash panel assembly, including the air ducts must be removed. Is this true, and can I find step-by-step instructions for doing this?

    PHR004
  • imidazol97imidazol97 Member Posts: 27,132
    edited October 2011
    > It appears that the entire dash panel assembly, including the air ducts must be removed.

    No. It can be done by removing the underdash hush panel (thin plastic) and taking off the glovebox door.

    If you want to email my email given in my profile (click on my user name at top of this post), I'll try to link you up with some help.

    The Bonneville has a different dash structure in that area than the leSabres. Yours is harder to get to.

    First, you need to verify that the electric actuator is not moving correctly, by looking through the hole in the brace behind the glovebox where you can see the rod that the actuator uses to move the door. If you find the actuator is bad, it can be removed by taking off two short screws--but they do it by feel since they're next to impossible to see.

    What happens is the actuators have a plastic gear inside that splits so it's not pressed against the hub and slips. The hub is what moves the actuator rod.

    I removed mine and glued the gear to the actuator. But mine is easier to replace if it breaks or slips again. So I decided I might not own the car by the time it comes loose from the plastic instant glue.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • ac82ac82 Member Posts: 1
    I am in the process of replacing the blend door actuator on my 98 Bonneville. I can not access anything behind the glove box so I removed the cover off the blend door / A/C coil box to get to the actuator motor...Now I can't get it to go back under the dash...It came out so I know it has to go back in! I am at my wit's end. I would appreciate any help!
  • budjenningbudjenning Member Posts: 1
    I'am having problem removing the programmer. I have removed the cover under the programmer, and the glove box, and can't seem to get any futher. I see the tubes going into the box, but now I still can't remove it.
  • diytosavediytosave Member Posts: 6
    I have a 1998 sse Boniville the blower motor would quit intermeditley now it quit working. I check the motor by running wires from the battery and it works great. Controls inside the car show the blower on any speed but nothing i have checked all fuses I show about 9.5 volts in the wires going to the motor. I have digital controlls. is that enough voltage? I don't know where the blower motor control mod is? or if that is even the problem or if the voltage is to low. I do know that there are three computers that control that system. Any help would be great as it is the wifes ride and I'm in the dog house untill i get it fixed.
  • imidazol97imidazol97 Member Posts: 27,132
    edited February 2012
    image

    image

    The location is where shown. Follow the wires from the blower motor up. The relay center above the blower control module is held by two screws. Remove those and it can be pushed upward with slack on the wires and give some room to get the BCM out of the airbox.

    The module is electronic. They will show voltage but no current. If the blower runs when connected directly to the battery on a fused line and with a ground, then you're probably needing the BCM for roughly $100? Available at Rockauto.com and other local box stores.

    If you do not have the digital speed control on the blower, then the same location would have a resistor set that gives three speeds.

    The only other possible problem is burnt contacts on the connections due to high heat. So take a look.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • sea_lifersea_lifer Member Posts: 1
    Trying to figure out what could possibly be wrong with my wifes car. When the A/C is on the cool air blows out from the floor vents just fine ( I think ). When you push the button to go to the vents on the dash board, the air coming out of the vents on the passenger side comes out cool but on the driver side there is a noticeable (hotter) difference. Does anyone have any idea what could be causing this. I thought it might be the blend door actuator, but the air itself is being diverted correctly, the only problem is the temperature of the air on the drivers side vents on the dash when it is on A/C. Any help that anyone can provide will help out immeasurably.
  • imidazol97imidazol97 Member Posts: 27,132
    edited March 2012
    You are dealing with three separate electric actuators.
    .
    One controls the direction of airflow for both systems, driver and passenger sides. That is not a problem since you can change the air flow path which is the same for both sides.

    One controls the air temperature blend door on the driver side.

    One controls the air temperature blend door for the passenger side.

    By removing the underdash plastic cover carefully, you can then watch the movement of each of these by the white center rotor on the electric actuator while you change the temperature demand on the dash with the key ON (I don't think the engine has to be running).

    I suspect you'll find the driver side is not moving all the way through the range of motion.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • wolfman2020wolfman2020 Member Posts: 5
    First thank you for all the great information.. I lost my highest fan speed and I looked at the illustration above but I cant tell if I replace the fan motor from under the hood or under the dash, can you please point me in the right direction on what I need to do Thanks WM
  • imidazol97imidazol97 Member Posts: 27,132
    Why would you replace the blower motor? If it runs on the 3 lower speeds, that means the fan motor is okay.

    Notice there is a separate circuit for the highest speed due to the high current draw. IIRC it has its own fuse in the relay center under the hood. AND it has its own relay. Either of those may have failed. The relay is in the relay center under the hood.

    If you are able to do some electric troubleshooting, test for power on the purple line to the blower motor when the fan switch is on HIGH and the key is ON. You probably are getting 12 volts on the other 3 speeds and then when you switch to HIGH, the voltage drops to zero.

    The cover for the relay center comes off easily. I do not know if there is a diagram in it showing which large fuse goes to which circuit. You may have to test each of them for 12 volts on both poles.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • wolfman2020wolfman2020 Member Posts: 5
    Thanks for the help I can definately do a voltage test to the blower motor,,Is the motor under the dash or under the hood? Or should I just check it at switch?? Thanks again WM
  • imidazol97imidazol97 Member Posts: 27,132
    Blower motor is on the firewall center behind the engine. It has a round cover with 5-7 screws holding it in. Follow the leads from the motor up to the top of the air passage that carries the air from the blwoer motor.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • wolfman2020wolfman2020 Member Posts: 5
    Thank you again it was the fuse and its working. Now Im having trouble with the engine shutting off intermitent. I think it may be the ignition switch because I can wiggle it and it will come back on. How does the switch come out, do I have to pull the steering wheel or is there an easy way to change it,,thank you again . I'm a motorcycle mechanic and working on cars tends to make me crazy
  • imidazol97imidazol97 Member Posts: 27,132
    edited April 2012
    The ignition switch itself is on the top of the steering column under the dash. It's linked to the lock cylinder at the top by some kind of rod. Many people think it's up at the top with the lock cylinder.

    Several H-body posters have had problems with the switch. Check rockauto.com for it and look for a 5% discount code that goes into the "where did you hear about us" box.

    To replace must not be terribly difficult from what folks in Pontiac forums have said. That's as long as you can get your body in there between the door frame and the seat or lie upside down on the seat and hang over down onto the floor. I worked under there on the diaphragms for the HVAC control valves, but I didn't check on how the ignition switch looked.

    Part #80
    I suspect you need to disable the air bags to do this.

    image

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • nburkholdernburkholder Member Posts: 2
    Hi,
    I have a 96 Bonneville and got the a/c fixed a few summers ago and then it went out again the next summer. I don’t want to dump a ton of money into it but it allows heat in on the floor board all the time. When i turn the blower on i can switch between floor, vent, and defrost, but when everything is off heat pores in from the floor board making summers miserable. What can i do so that when the unit is off no air comes through any port?
  • nburkholdernburkholder Member Posts: 2
    Hi,
    I have a 96 Bonneville and got the a/c fixed a few summers ago and then it went out again the next summer. I don’t want to dump a ton of money into it but it allows heat in thru all vents, floorboard vent, and defrost at all times. When i turn the blower on i can switch between floor, vent, and defrost, but when everything is off heat continues to flow in thru all vents though the blower is off. Please help!!!
  • tgonyatgonya Member Posts: 3
    I have a 96 Bonneville with 200K milage and have been experiencing the heat issues that evidently many other bonneville owners have suffered. (i.e. the system closes the blend door after about a minute of operation and only cold air comes out after that).

    Reading through all the various discussions on this particular issue (and trying all the various solutions offered), I've come to the conclusion that it's something that is a) quite common to this particular heating system, and b) even if I replace all the electronic parts (have replaced the "head unit" already), there's no guaranteeing this won't happen yet again.

    So, my question here is simply how do I go about disconnecting the actuator motor (hopefully without damaging it) to where the blend door stays in the "heat position"? Any pictures would be GREATLY appreciated!

    Thanks in advance for any and all help offered!

    Signed,

    Tom, aka Cold in Allentown, Pa :(
  • tgonyatgonya Member Posts: 3
    By the way, just so we're on the same page so to speak, this is a picture of the dashboard...

    image
  • imidazol97imidazol97 Member Posts: 27,132
    Most likely your actuator has had a gear inside crack which reduces the pressure fit it has on the axle which extends out of the actuator to actually push and pull on the rod to the blend door.

    The Buick has easier access to this actuator than the Bonneville due to a different design of the dash. Some had pulled the glovebox door forward so they can see through to the top of the heater box or removed the door. There is a view to the rod which has a brace rod in the path but there is a hole in the brace allowing a view of the rod. They have actually ducttaped (IIRC) a clothes hanger wire to the rode to be able to manually adjust it, i.e., keep it from moving on its own.

    The actuator can be removed by two screws and disconnecting the electrical connector, but space is tight. Use methods to avoid dropping the screws or losing the sockets if they come off your wrench.

    Here's a link: link title

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • tgonyatgonya Member Posts: 3
    Thank you VERY much! The link you provided gave me the clue to look through the inspection hole behind the glove box...

    image

    The actuator rod is (barely) visable through the left (drivers side) hole which I circled in red.

    Here's a close up, although, I couldn't get my camera to focus on the rod itself.

    image

    It was a simple matter to take some bailing wire, loop it around the actuator rod end, pull it towards the passenger side of the glove box (which opens the door for heat evidently), and tie it off. That will keep my wife (not ot mention my marriage) warm for the winter. :)

    To actually get at the actuator motor looks to be a real challenge and if my 200k Pontiac makes it through the winter at all, MAYBE I'll attempt to replace it come spring.

    Thanks again!
  • imidazol97imidazol97 Member Posts: 27,132
    I took the slipping actuator off my leSabre and used superglue between the white nylon gear and the gray plastic axle to hold it. I figured if it didn't hold, I just remove it again and replace. But the car has nearly 200,000 miles and I never know how long I'll keep it.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • robonnie96robonnie96 Member Posts: 1
    This is great timing! My 96 Bonneville SE has 135K & has the same post battery replacement/ACC issue as mentioned by "tgonya". I have just replaced the thermostat & heater issues not fixed (wish I had been on here 1st). The dealer diagnosed it as the A/C Programmer & $700 for the part just today. Not going there! Will try the Air Mix Actuator recommended by "imidazol97" & pictured by "tgonya". Thanks a bunch guys! Will let you know the outcome.
  • imidazol97imidazol97 Member Posts: 27,132
    If you do anything that disrupts power in your car, use the key ON and turn the HVAC controls to OFF and let the unit shut down. Many people think that when the unit is left mid position and then power is restored it breaks the gear or forces a slipping as it does the startup movements to max heat and then max cool to locate the positions for the computer. This may only apply to the auto control unit, but I'd shut down the manual unit too to protect its actuator.

    I'm really glad that something I've learned from the past adventures with my H-body and reading other's posts has helped someone here. I appreciate it when someone comes back and says it did help.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • stew20stew20 Member Posts: 2
    Hi, I've owned this car since new. A couple of years ago the blower started working intermittently. I would set it and it would come on when it wanted to. I have noticed that it would seem to speed up as the engine RPMs increased. That makes me think vacuum leak. I just put up with it, but now it has it has pretty much ceased to function, though it did come on last weeks for a couple of seconds. I had frost on the windshield so I had it in the defrost mode. Eventually, the warm air rose on it's own and partially cleared the windshield. I don't think I have a heat issue, just getting the fan to work. Does anyone have any ideas?
    Thanks
  • imidazol97imidazol97 Member Posts: 27,132
    What kind of HVAC system do you have: manual or automatic with digital readout.

    If it's the digital readout, you have a blower speed module that can fail in strange ways. Or it could just be the blower motor is failing. The motor is about 5 screws on the firewall on the back of the engine compartment.
    The blower speed control module is above the motor sitting down into the air path for cooling.

    The Relay Center above that is held in by two screws and can be raised if they're removed for easier access to the two screws hold the BCM in place.

    If you ahve the manual system it's most likely the blower motor. Intead of the module, the manual system has a resistor pack for changing speeds.

    The motor can be tested in place with a fused lead from the battery to the purple wire. You have to also provide a ground for the black wire.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • stew20stew20 Member Posts: 2
    I have the auto digital as pictured in Post #221. So, if the motor doesn't work with the test lead, I'm looking at replacing the blower speed control module? Are these parts available at most auto supply stores?
    Thank you very much for your help. I'm going to get on this this afternoon.
  • imidazol97imidazol97 Member Posts: 27,132
    > the motor doesn't work with the test lead

    No. If the test of the motor using a fused power wire from the positive battery terminal to the purple wire and a ground to the black wire makes the motor run just fine--at full speed--, then you _probably_ have a blower control module problem.

    They are available from rockauto.com, and various box stores, along with the recycling yards. Depends on how much you're willing to fuss over it from recycling, such as the pick-and-pull yards.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • 1howard1howard Member Posts: 1
    edited February 2013
    I am amazed how long this thread has been going. This has to be a design weakness in the Pontiac. I had the same problem but it could go either way, hot in the summer, cold in the winter. I didn't want to work on the problem by having the dealer throw my money at it. The fix I show has been in place for at least four years (just checked, can't believe it was May 2005) and almost always works. I concentrated on the nylon pivot for the control arm and use that to move it back and forth from hot to cold. When it is working changing the temp from hot to cold you can see the arm moving if the glove box door is open.

    I upgraded the arm to metal from wood several years ago. There are times it jams to the right (cold) and I don't want to force it. Usually turning the climate control off completely will allow me to move the arm. Fortunately the car is narrow enough to reach the arm while driving w/o dropping my cell phone, spilling my coffee or losing my donut. :-)

    Here are some pictures and description that may help you understand what I did, but not necessarily motivate you to do it.
    Howard
    http://home.comcast.net/~bmy1398/Car_Heater/Climate_Control.htm
  • joshandmeganjoshandmegan Member Posts: 2
    I have a 2002 Pontiac Bonneville and the heat works on high and high only I have no control functions and no read out screen we were driving down the road and the light on it started to flicker and when it did it just kicked to high heat and and high fan mode and now it is stuck there but it seems to be in auto mode cause it gradually increases in fan speed I have taken apart the whole dash and looked for loose or chafed wires and no luck then I bought a new heat control head unit and nothing if any one has any ideas I am open to thoughts
  • imidazol97imidazol97 Member Posts: 27,132
    edited October 2015

    I have a 2002 Pontiac Bonneville and the heat works on high and high only I have no control functions and no read out screen we were driving down the road and the light on it started to flicker and when it did it just kicked to high heat and and high fan mode and now it is stuck there but it seems to be in auto mode cause it gradually increases in fan speed I have taken apart the whole dash and looked for loose or chafed wires and no luck then I bought a new heat control head unit and nothing if any one has any ideas I am open to thoughts

    I'm going to take a WAG. I have had 2 leSabres with this same blower setup and I'll assume your 2002 Bonneville H-body is the same as my 2003 leSabre H-body. The blower control module can fail and do various things in previous vehicles. One is default to high blower and another was in some earlier versions could stay on after the key went to OFF.

    But looking at the troubleshooting flow chart for blower in my 2003 factory service manual, it reminds us to check the connector to the blower control module. These connector could have corrosion or just heat cause the contacts to not make good contact. The plastic holder then could soften that holds the contact blades and the blades then further lose contact and burn. Then I recalled a few people through the years have found the connectors damaged.

    The blower control module is an electronic variable power transistor that can vary the power to the blower motor and provide feedback to the control head as to what power it's running the blower at. Because of the way you describe its going back I suspect the burned contacts or softened plastic. The power leads from the blower motor go to the blower control module which is mounted on the side of the HVAC blower area. It has to have the heat sink cooled by the airflow so that part sticks into the blower case.

    The factory manual says there a dash integration module in the way to getting to the blower control module on the side of the case. So it has to be removed first--at least on the 03 leSabre.

    If it's not the connector, I'd suspect the blower control module itself. You've already replaced the dash control IIRC. You can get the BCM (blower control modules) from pulls at junkyards now. If it's the plastic connector that failed, you probably can get a replacement but might be easier to replace the blower motor. Your can, I BELIEVE, is in the group where the replacement motor is adapted to get away from the original bolt in method. Check carefully if you use a wrecking yard or pick and pull yard to be sure to get a motor that's the same.

    Rockauto.com has the BCM for about $85 plus ship plus tax for ACDelco
    I didn't look at blower motors or to see if they offer a replacement connector
    to splice into the wires. The HELP parts by Dorman at lots of parts stores may
    have connector replacements. They always seem to have things like that.
    If it is the connector being fried, search Dorman Help on the net to see what
    parts they offer.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • joshandmeganjoshandmegan Member Posts: 2
    edited November 2015
    Everything shuts off with the key.....it illuminates the controller but no power to the actual control parts of the controller and my girlfriend has already replaced the blower motor
  • montemonte Member Posts: 1
    has anyone come to a conclusion on the problem Mike235 is describing? i have to same issue with my 99 SSEI. no matter what iv tried, after 30 seconds are so the interior temo begins to flash and the blend door moves all the way back to the left giving me no heat. if the engine is warm or cold, it doesnt matter. Every time i turn the car off and either turn it on or restart it,,,,the blend door arm moves to the right for heat and after about 30 seconds the ECC starts the flash the int temp and the arm goes back to the left,no heat! Cooling system is full, all hoses hot. and as ive said, if the engine is warm, i get heat from start up for about 30 seconds until the ECC flashes the interior temp which then the actuator arm moves back left and closes off the heat.
  • imidazol97imidazol97 Member Posts: 27,132
    Without checking the design of that system, I assume it uses the same temperature blend doors that a 98 LeSabre uses with the dual temperature control system.

    I suspect the system is trying to do the system check on startup where the temperature is run all the way to maximum and then back to minimum to set where the limits of travel of the electric controls are for the blend doors. Those modules can be watched during this process by looking under the dash on the passenger side after taking off the plastic sound layer.

    If you locate the one for the driver side, I believe it's on top of the box without looking again, you probably can take hold of the lever and move it with the hub sliding on the gear that's inside the module. The gear has cracked. Or the crack has occurred in the middle of the travel range causing the system to balk.

    It will take a while, but I'll post pictures if I still have them linked. The modules are inexpensive and can be replaced by owners who are lithe and have relatively small hands. You may want to take off the glove box door if yours is like the leSabre's.

    Parts are available from Rockauto BUT you have to be very careful of the labeling and be sure you get the module for system--check your RPO label on spare tire cover for CJ2 or the other system label, which I can't recall right now.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • imidazol97imidazol97 Member Posts: 27,132
    Here's a link to a Pontiac version. Down around the pictures like #15 or so you see the electric actuator with the rod that moves the blend door inside the heater box. The metal rod snaps onto a white nylon connector--it looks like it's threaded but it's just ridges to avoid slipping.

    Other pictures show the broken gear I mentioned. It the crack in the gear is at a place where the motion of the actuator hits it with the gears meshing inside, it might be causing the startup testing to fail. It's also possible the blend door is blocked inside the heater.

    You can unsnap the rod and manually move the heater door with the engine running and blower on to see if the heat adjusts up and down.

    Notice at one point this article shows how the owner put a clothes hanger onto the end of the blend door rod with duct tap so he could move it from the top of the instrument panel, through the glove box IIRC.

    2014 Malibu 2LT, 2015 Cruze 2LT,

Sign In or Register to comment.