This 2004 Chevrolet Impala came in with the complaint that there was no heat on the driver’s side of the car. It could very well have been the reverse, no a/c on the driver side as the problem turned out to be a faulty driver’s side blend air door actuator assembly. There was a code B0408 stored for the that actuator. If you do not have a way of checking for codes, the actuator should be watched to see if it responds to command inputs. When there is a no or poor heat condition the coolant level should always be checked first.
To access the actuator the lower dash cover has to be removed but first the cover on the left end of the dash has to come off.
Then the driver’s side hush panel.
There may be a couple of screws along the lower edge of the panel. After they are removed the cover will pull off the dash and the trunk release switch can be disconnected if present.
Four 10 mm headed screws are recessed behind the metal knee bolster and there are several 7 mm headed screws around the exterior of the panel.
You can now see the actuator in the center of the following picture. The white label is easily visible. Testing is difficult at best but here is what needs to be done if you do not have a scan tool that will interface with the system. Back probe the yellow wire and the dark blue/white wires with a voltmeter. There should be 0 volts for a stationary command. There should be a 12 volt positive for a commanded movement and a negative 12 volt reading in the opposite direction. Note that the code may have to be cleared before the control head will make the commands. Use a scan tool, disconnect the battery or remove the DIC/RKE fuse for at least 60 seconds.
This is what the actuator looks like out of the vehicle. The screws holding the actuator to the case should have 5.5 mm heads. To order this actuator please click here.
After replacement of any of the actuators a recalibration procedure needs to be performed. It is very simple though. Turn the ignition off, remove the DIC/RKE fuse from the right / passenger side, interior fuse box. It is a 10 amp fuse. Leave the fuse out for at least 60 second. Install the fuse and turn on the ignition. Do not touch the a/c controls for at least 60 seconds. switch the key off for at least 10 seconds and the recalibration will be complete when you restart the engine.
Re: Calibration
Is there a recommended temperature setting to set the controls at before I start this replacement? Should it be completely off cold/cold?
Does it matter?
Glad your heat is working and you are correct, you did some unnecessary steps. The actuator does not have to be disassembled and re positioned. Instead the door shaft simply needs to be rotated by hand to match the new actuator. Then you should perform the recalibration step by removing the appropriate fuse as outlined in the article.
followed the instructions and now working 3 days. but i may have done a lot of unnecessary work. when I initially installed cold air still blew out. i went back and forth between the old and new actuators. finally I decided to keep the new one installed. later on that night while driving the car seemed to become really warm. I had the driverside vents closed. It’s a miracle….there was heat. I did have to take the actuator apart to install. the actuator is installed to car with two screws and a setting rod. i took apart the actuator to position for the setting rod. unsure why i needed to do that but it worked and I am very please and greatful the I found the instructions that may have saved me around $300. Thanks Sparky
I just had the same prob with my 2004 Impala. I read on the Chev forum where a guy just tapped the actuator and it started working. I already had things pretty open, replacing the instrument cluster, and the heater driver side stopped working. I tapped the actuator pretty good with a ratchet and viola.
Don’t know how long it’ll last, but I know that’s the prob.
iSparky, as I stated above, I didn’t have a code. And for all others, my symptom was cold air driver side, with the passenger side being luke warm at best.
There are two small wiring harnesses that were in the way after I removed the two bottom covers; I tugged on them and got them loose; it gave me a better access to the actuator. My actuator had two screws; the engine side bottom was accessible with a straight 14″ 1/4″ extn on my 7/32 socket, the trunk side top I had to use the 45 deg adapter. It was easier with the 14″ extn. The top engine side hole was for a an alignment pin/stub.
As soon as I unseated the actuator, it started rotating for maybe a min or so; I didn’t turn on the ignition. Since my car was warm, I started it up, turned on the heat on high, reached in and turned the shaft that the actuator turns. Heat was cranking now on both sides. I knew the actuator was the problem.
Installation was easier than the removal, especially with those two harnesses dangling loose. I was able to hand start both screws.
Sparky, thanks for this great tip.