My HVAC won't light up

[bigwhite93]

I think my lights are burned out, at night when you turn the headlights on the buttons don't light up, only the little display screen. Do these even have lights in them? If so, how hard is it to replace the bulbs?

[someotherguy]

It's not that bad, though it could be a little tough finding the bulbs themselves.

If you look carefully at the a/c controls you'll see tabs near the front that need to be undone so you can crack open the shell. If you don't pay attention you're gonna break it.

Inside there's the circuit board and it has twist-in mini socket bulbs that I'm not sure where to source; haven't had to find any yet. I'm betting someone else here has though and hopefully has the source/part #. Maybe the dealer but I bet they just want to sell you the whole control.

Richard

[bigwhite93]

Thanks for the info, I have another HVAC unit out of an 88 I may try to get the bulbs out of. Does the factory radio use the same bulbs? If so, I have it laying around and I think they still worked.

[someotherguy]

Dunno...never bothered to crack open a factory radio. They're usually the first thing to go when I get a truck. :D

I took a quick peek at an 88-94 AC control to remind me of the trick to open it up. It has two screws on the back of it. Remove those, then look closely - you'll see the tabs I'm talking about. If you're looking at the rear of the unit with it right-side-up, bottom left corner (think: "behind" the off button) you can slide the housing around the tab, then the tab on the right should be easy to pop loose. Then the whole rear of the housing slides off the circuit board. DON'T ZAP THE CIRCUIT BOARD WITH ANY STATIC ELECTRICITY...ground yourself by touching something metal first; it takes less static electricity than you can feel to ruin some chips.

You'll see the back of the bulbs; two of them are trapped behind the circuit board you just slid the housing off of. Don't sweat it; it's just stuck to the other circuit board by being crammed against that foam tape, it just lifts away. Then you can use a screwdriver to twist the bulbs loose.

http://www.someotherplace.com/guides/8894acs.jpg

Richard