HVAC Button Lights

**Red94Chev** · 12-28-2007, 10:57 AM

I bought my truck used, so I don't know if these lights ever worked. Are there supposed to be lights behind these buttons?

I think I remember they were working when the original radio was installed, but I replaced the radio with a CD unit many moons ago. I know there are three lights for the buttons in the HVAC unit. It would be nice to get these lights working again if I can. Any thoughts or suggestions?

**BHB** · 12-28-2007, 02:26 PM

They do not illuminate in my '94. I seem to remember them lighting up in my '88 though.

**Striker49** · 12-28-2007, 02:49 PM

My 88 HVAC does light up.

**hornsfan10609** · 12-29-2007, 05:25 PM

They are supposed to light up, they all have bulbs in them. All of mine are burned out and haven't worked since I got my truck in May 06. You can supposedly buy the bulbs at radio shack, but they don't have them in the one by my house. I think the bulb is an 1893 or something, but don't quote me on that. You might be able to replace them with LEDs.

**Striker49** · 12-29-2007, 05:31 PM

More than likely, if they're just "plug-n-play" blubs then there is a LED somewhere for it. I havent had my HVAC apart in a few years, but I'm wondering if it's possible to remove the green tint similar to what I did for my 91 cluster. There is a write-up here on changing the display, but haven't seen the buttons yet.
/unhijack

**Crews Customs** · 12-30-2007, 12:43 AM

i have 1 all apart in a ziplock bag at the shop. ill look next time i go there & see what kind of bulbs. i want to fix mine also, i hate not having them light up.

**beater truck** · 12-30-2007, 07:12 AM

the bulbs are replaceable, but they are soldered into their holders so the entire tiny assembly has to be replaced. When I got my '94 last year I tried the dealership first for new bulbs, they didn't even have a listing for them. They sent me to a local electronics store that could order them, but they were about $8 each.

Being the cheapskate that I am, I wasn't about to drop $8 apiece for new bulbs, so I bought some 'grain of wheat' bulbs for .75 each, drilled out the center of each bulb holder for a snug fit of the new bulb and 2 #50 holes through the bottom for the wire leads to pass through.

A dab of hot glue on the bottom of each bulb held everything in place. I plugged in the bulb holder to the circuit board, then soldered the wire leads to the circuit board. The whole operation took about 2 hours to fix all of the burnt out bulbs on the HVAC and stereo controls.

I wanted to use LEDS but I couldn't find any that had the built in resistors for 12V use and there wasn't enough room to mount a resistor anywhere on the bulb holders. Hope this gives you an idea!

**88GMCtruck** · 12-30-2007, 10:27 AM

I changed my bulbs out for blue leds. I soldiered them right to the board.

**Crews Customs** · 12-30-2007, 11:13 AM

i wish someone had pics on how to solder them to there. electrics is most def. not my specialty.

**hornsfan10609** · 12-31-2007, 09:26 AM

I'd rather find the regular bulbs for cheaper. beater truck, do you remember what number the correct bulb was?

**chriskelley2003** · 12-31-2007, 12:21 PM

i just swapped to LEDs on my 98, bought em from www.superbrightleds.com ... in the LEDs its a T1.5 instraument bulb, dont know on the regular bulbs

**beater truck** · 01-01-2008, 08:52 PM

Originally Posted by hornsfan10609

I'd rather find the regular bulbs for cheaper. beater truck, do you remember what number the correct bulb was?

no, sorry. I don't have any idea what the OE part number is. If you pull one of the bulbs and take it to a good electronics repair shop (not radio shack) they can look up a replacement bulb for you. The place I got the grain-of-wheat bulbs was a repair facility for Alpine car stereos.

**hornsfan10609** · 01-02-2008, 09:39 AM

I was just looking for the number of the bulb, you know how bulbs are numbered like 194 bulbs or 1157 bulbs? So if I go to a shop I can just tell them the kind I need.