I took out the center heating control unit and stereo to fit the Aux-In unit and everything was working perfectly until night-fall when I noticed that the three center bulbs were not working in the heating control knobs (just the center bulbs for the Heating Screen, Air Flow, and A/C, everything lit on the rest of the panel and all the controls worked including the three centre buttons. Also the Snow and Trc Ctrl bulbs were not lit.
After driving for a while the Snow and Trc Ctrl bulbs re-lit but after pushing the buttons they went out again, loose connection I thought, but I've pushed everything home and tried to check for loose wiring.
Anyone give me a couple of clues?
* Can you take the Snow Trc/Ctrl unit apart to check if the bulbs are sitting firmly, if so how?
* Is there a common colour of wire for the light feed?
* Is there a fuse that might cause the strange three bulb only issue on the heater control?