| ID | Status | Date | Year | Make | Model | Transmission Type | A/C Controls | Public/Private |
|---|---|---|---|---|---|---|---|---|
| #13040 | Closed | 2004 | Chevy | Trailblazer | public |
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A few months ago, all the controls on my climate control panel went out. I can still change the fan speeds but a/c, recirculation, and fan mode all went out at the same time. Recently, I found out the car battery was bad. Replaced that. Tried re calibrating the HVAC system via your tutorial but made no difference. I listened for any noises during the re calibration and didn’t hear anything. I’ve tried replacing the climate control panel first but made no difference. On the forums at GMT Nation some people have said it very likely could be the actuators. I went ahead and bought a defrost, mode, and driver side temp control actuator. I’ve taken the driver side panel off below dash and tried taking the floor duct off but am stuck at this point. I cannot figure out how to remove the floor duct that is above the driver’s side gas pedal. I’ve included a picture of it. It wraps around the gas pedal and connects to the center console. |
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It looks like you have adjustable pedals. If so the gas pedal (APP Sensor) has to be removed in order to gain access to the actuators. I personally have never had to replace the actuators on a Trailblazer with adjustable pedals so I don’t have a repair article on the needed steps to do so. |
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Thanks Sparky. I ended up being able to remove the old ‘mode’ actuator with my left hand. I found out testing with a power probe that the old actuator worked when powered up. After replacing with new actuator it made no difference. I’m now thinking its an entirely different problem… |
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Statistically the mode actuator is the primary cause of the problem although over the years we have found the defrost and temperature door actuators at fault also. Just to be sure the mode actuator that you replaced was the one on the driver’s side with the white gear cog attached, correct? |
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Hey Sparky, I gave it my all today and spent the entire day trying to figure this out. I talked with a GM tech on justanswers.com and he walked me through all the troubleshooting steps and guess what?? It was the orange wire on the blue connector to the hvac unit. It didnt have any power. As soon as I applied 12v with the power probe all the functions worked including the ac/recirculation/modes everything!! I’m so ecstatic to finally find the culprit. Next monday am going to try and replace the orange wire. The actuators were not the problem. |
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The small orange wire at the rear of the control panel is powered by the HVAC B fuse in the rear fuse box. The rear fuse box is under the rear seat on the driver’s side of the vehicle. The fuse should have battery power at all times. |
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Yes, I tested the hvac b fuse, hvac 1, and the third hvac fuse. They all lit up. Even that being the case there was still no power to the orange wire. So I will need to first open the rear fuse box to check the internals. |
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Before taking the rear fuse box apart I would recommend removing the fuse and checking for signs of corrosion or arcing on the fuse blades. Check to make sure the 7 mm bolts are not loose. They secure connector bodies to the underside of the fuse box. If all of that is okay lift the fuse box up and check for power on the orange wire located at terminal slot C1 of the black 68 terminal connector body. If your Trailblazer has rear air there will be two orange wires in that slot. Also if you have rear air check to see if it works okay. If it does that should eliminate the fuse box as a cause of the issue. The GM diagram does not show any other connectors between the rear fuse box and the HVAC control panel so if both ends are okay the wire is damaged somewhere in between. That would be highly unlikely but possible. If the radio has been replaced the wire may be cut in that area. If there is any sign of moisture under the carpet the wire may be corroded in half under the carpet. |