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.
May or may not be your problem but you certainly do not want to waste time or money until the basics are checked.
so you think it could be low engine coolant even though there is heat on the passenger side?
As long as it was a quality part the actuator should still be good. You need to take a look at it while someone adjusts the temperature to see if the actuator is responding to commands. There is a slight chance that your engine coolant level could be low.
Hi Sparky,
Thanks so much for this page. I fixed the problem described and had heat from the drivers side after replacing the actuator.
I also had a problem where water was coming in the vehicle from just under the windshield on the passenger side caused by a diverter that had fallen off. I fixed that also. As a result of the water that had entered the wires to the speakers had corroded to the point where I had to splice the wires. After having repaired the radio/speakers the actuator heat on the drivers side isn’t working again. I’ve tried resetting the actuator however it hasn’t worked. Do you think I need to buy a new actuator, and how common is it that they fail after less than 1 month?
My husband did exactly what it said about the actuator and now its nice and toasty inside the car! Thanks Sparky!