Fixed My Auto Climate Control Problem
mazingo
10-03-2008, 01:19 AM
I recently purchased a 1998 GMC jimmy with 223,000 miles on it from my wifes's uncle. It runs great but he told me he could not get the ACC to work right.
I fixed my Auto Climate Control by gutting the mixture control motor and hooking it up an a double-pole two-circut monmentary switch. Now I can control the temperature. I will try to post the instructions soon.
I fixed my Auto Climate Control by gutting the mixture control motor and hooking it up an a double-pole two-circut monmentary switch. Now I can control the temperature. I will try to post the instructions soon.
mazingo
10-03-2008, 02:28 AM
To hard wire the Mixture Control Motor you will need a double-pole two-circuit momentary switch, some wire, electrical tape and some connectors for the switch terminals, about $10.00 worth of stuff at radio shack vs. $100.00 or more at a dealer.
The switch is the most important part. It can be a rocker style or a toggle style but it has to be a double pole two circuit momentary switch. The description should say something like "Momentary-On / Off / Momentary-On DP 2 Circuit". It needs to go back to the off position when you release it.
Removed the Mixture control motor
It is located behind the glove box. You will have to remove the vacuum actuator that is in front of it (it slides up and will lay out of the way). There is a wiring harness going to the motor try to disconnect it. If you can’t get it off, you may be able to remove the motor with it attached. There are some small screws holding the motor in place they are either ¼ or 5.5mm can’t remember what I used. Take them out and the motor will shake or wiggle loose. I forewarn you it is a tight area to work in.
Once you have the motor out you can open the motor case by prying up on the ears, but try not to break them because they hold it together along with the mounting screws.
When you open it you will see some gears, take them out. You will see a plug with two wires, unplug it. You will see a motor, pry it straight up and out of the case, but don’t bend the shaft of break the mounts. You will see a circuit board, take it out.
Attach some wire to the two wires coming off the motor, they need to be long enough to reach you switch. Do this however you want as long as the wires stay put and are insulated. Put the motor back in the case. LEAVE THE CIRCUIT BOARD OUT! Put the gears back in the case. You can check them for wear if you like. Try to put the output gear in the center position. There should be some alignment lines on one side of the case.
Drill a small hole in the topside of the motor case just big enough to pull the wires through. Pull the wires through the hole and then snap the case close. Test the motor on a 12 volt source, you will notice the if you reverse the wires the motor will turn in the opposite direction.
Put the motor back in place and then the actuator back in place. You can also wait until you verify the switch and motor work before you put every thing back in place.
Find a good location to mount you switch, preferably one easy to get to wile driving. I mounted mine to the left of the center dash vents on the blank panel used for the 4WD controls (I have a 2WD model). You will need to run 12-volt wire to the switch and a ground wire. I tied in to the rear wiper control and grounded it to the radio mounting screw.
To wire the switch up you will need to put the incoming power on the center terminals of the switch. Then put the wires for the motor on the bottom two terminals. Then run a jumper wire from the top left terminal to the bottom right terminal and from the top right terminal to the bottom left terminal. If you are familiar with electrical components feel free to wire the switch up to your liking.http://i88.photobucket.com/albums/k200/bmazingo/switch.jpg
Make sure the switch and motor work in both directions. Then you can put the motor and actuator back in place if you have not done so. You may have to move the mixture door manually to get the motor to line back up.
Start the vehicle and let it warm up. Turn the fan to full (easier to hear the mixture door change position). Hold the switch in one position for about 5 seconds and then the other position for about 5 seconds. You should be able to tell when the door go to the heat position by the change in air temperature and the sound of the air coming out should change (quieter).
Mark the hot position and the cold position. You are DONE!
With the momentary switch you can stop the mixture motor in any position and control the temperature of the air. So it is a lot better that the All-Hot or All-Cold method that most people get to experience when the Auto Climate Control goes crazy.:runaround:
The switch is the most important part. It can be a rocker style or a toggle style but it has to be a double pole two circuit momentary switch. The description should say something like "Momentary-On / Off / Momentary-On DP 2 Circuit". It needs to go back to the off position when you release it.
Removed the Mixture control motor
It is located behind the glove box. You will have to remove the vacuum actuator that is in front of it (it slides up and will lay out of the way). There is a wiring harness going to the motor try to disconnect it. If you can’t get it off, you may be able to remove the motor with it attached. There are some small screws holding the motor in place they are either ¼ or 5.5mm can’t remember what I used. Take them out and the motor will shake or wiggle loose. I forewarn you it is a tight area to work in.
Once you have the motor out you can open the motor case by prying up on the ears, but try not to break them because they hold it together along with the mounting screws.
When you open it you will see some gears, take them out. You will see a plug with two wires, unplug it. You will see a motor, pry it straight up and out of the case, but don’t bend the shaft of break the mounts. You will see a circuit board, take it out.
Attach some wire to the two wires coming off the motor, they need to be long enough to reach you switch. Do this however you want as long as the wires stay put and are insulated. Put the motor back in the case. LEAVE THE CIRCUIT BOARD OUT! Put the gears back in the case. You can check them for wear if you like. Try to put the output gear in the center position. There should be some alignment lines on one side of the case.
Drill a small hole in the topside of the motor case just big enough to pull the wires through. Pull the wires through the hole and then snap the case close. Test the motor on a 12 volt source, you will notice the if you reverse the wires the motor will turn in the opposite direction.
Put the motor back in place and then the actuator back in place. You can also wait until you verify the switch and motor work before you put every thing back in place.
Find a good location to mount you switch, preferably one easy to get to wile driving. I mounted mine to the left of the center dash vents on the blank panel used for the 4WD controls (I have a 2WD model). You will need to run 12-volt wire to the switch and a ground wire. I tied in to the rear wiper control and grounded it to the radio mounting screw.
To wire the switch up you will need to put the incoming power on the center terminals of the switch. Then put the wires for the motor on the bottom two terminals. Then run a jumper wire from the top left terminal to the bottom right terminal and from the top right terminal to the bottom left terminal. If you are familiar with electrical components feel free to wire the switch up to your liking.http://i88.photobucket.com/albums/k200/bmazingo/switch.jpg
Make sure the switch and motor work in both directions. Then you can put the motor and actuator back in place if you have not done so. You may have to move the mixture door manually to get the motor to line back up.
Start the vehicle and let it warm up. Turn the fan to full (easier to hear the mixture door change position). Hold the switch in one position for about 5 seconds and then the other position for about 5 seconds. You should be able to tell when the door go to the heat position by the change in air temperature and the sound of the air coming out should change (quieter).
Mark the hot position and the cold position. You are DONE!
With the momentary switch you can stop the mixture motor in any position and control the temperature of the air. So it is a lot better that the All-Hot or All-Cold method that most people get to experience when the Auto Climate Control goes crazy.:runaround:
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