Want this question answered?
behind the golvebox
The climate control amplifier is partially responsible for receiving requests from the control head (the buttons that you push), and sending commands to the servo to execute the climate control changes you requested. Example: I have a 1980 450 SEL. The climate control amplifier is behind the glovebox. I'm in the process of refurbishing mine with new guts. I knew mine was bad because the heat wouldn't come on.
If I understand your question correctly, a burned out dash bulb behind the display.
check your fuses in the main fuse box first, located under bonnet in front of driver. there should be a reference in the fuse box of which fuse supplies the climate control fan. Otherwise if Ok then chk the Relay located behind the fuses
First of all, are the dash lights also out......if so, the rheostat behind the instrument cluster may be the cause........
Behind a plastic cover in back of the battery, it is a black box about the size of a pack of cigarettes. One is the fuel pump relay the other is the kilma or climate control relay. You will see the fused OVP relay also.
the climate control wires all unplug at the actual control module behind the dash then just disconnect all the other electrical and vaccuum lines. And pull the bolts out
behind the glove box
DRL module
Up under the passenger side plastic protector - almost behind the glove box. You will see the air tubes & wires running into a black box there - that is the climate control module.
Remove the cover around the controls and you will see the bulbs inside the climate control unit. It just pulls off.
pull the heater control knob off and located behind is a small capless bulb pull out and then push in new bulb replace knob job done