Quick update. I removed my remote radio controls and measured the bulb sizes. They are T-1 (diameter = 1/8" = 3.2 mm) not T-1 1/4.

 

I did an experiment and was able to determine that these bulbs are most likely rated at 14V and 40mA. What I don't know is the light output (lumens or MSCP=MEAN SPHERICAL CANDLEPOWER.) It is likely 0.09, 0.12 or 0.15 MSCP.

For these applications, life-hour ratings of at least 10,000 hours seems typical.

 

Got the new bulbs mounted. Took me all of 10 minutes.

They are easy to remove from the small circuit boards. Just apply heat from the tip of a soldering iron to the solder pads on either side of the bulb base/holder. Once removed from the PCB, the bulbs pull out of their little off-white plastic holders. Then you peel off the blue silicone bulb cover and transfer it to a new bulb.

The bulb is put back into the holder by inserting base-first, the wires bent like the original around the holder and under the holder base, and the leads trimmed.

To solder, hold bulb and holder in place with a finger so that the leads are over the solder pads and heat the solder exposed on either side of the bulb holder. This melts the solder and it will bond with the leads.

Bulbs used:
size: T-1, 14 V, 40 mA, 0.15 MSCP, Filament type C-2F, average life hours rating: 16,000, Mouser.com part number 560-23.

P.S. I had a hard time opening up the plastic body that contains the PCBs. Be careful and don't rush. These were never intended to be serviced but they do come apart and can be snapped back together. I tested the bulbs before I reassembled mine because I did not want to have to reopen the switch bodies.

 

Yeah they're definitely very easy to break if you're not careful.

Any reason you didn't try to go the route of LED's? Just out of curiosity.

 

Yeah, good question about the LEDs.

I figured first that the original bulbs had lasted over a decade (most going on two) and that if I was careful in the selection of the replacement bulbs, I could get similar lifespans from the new ones. To this end, I found that not all 12V-14V T-1 (or for that matter T-1 1/4 bulbs) are created equal. Their rated expected lifespan can range from 1,000 hours to 100,000 hours. (for a selection of T-1s, see https://www.mouser.com/ds/2/208/WT_S..._T-1-29249.pdf) For reference, 10,000 hours is equivalent of the bulbs being on for about 2.7 hours per day, every day consecutively, for 10 years.

To confirm the right selection, I looked at what online vendors have been selling as replacements for these bulbs for our GM parts but I also used some simple test and measurement equipment to check the current draw at 14V to confirm the bulb identification.

Secondly, to install the LEDs would have necessitated working out the value of the series resistor that would provide provide a full range of dimming like the incandescent bulbs can do. Too high a resistance and it would never get very bright. Too low a resistance and there would be no appreciable dimming even if the dimming switch was at its minimum. Furthermore it would have been difficult to work out how to incorporate the series resistor into the circuit on the PCB.

Basically, I went with what worked and was easiest to do with minimal risk.

 

fair enough just curious

 

Haha, nice work. I just figured there wasn't any lights in them since none of mine work... definitely subscribing to this so I can replace them I feel like it.

 

All in all, it was not too bad. Blazen_red_4x4's pictures were a big help.

The only part I was a bit scared of was taking out the airbag. I printed out the instructions from my GM manual and everything was fine. It was a little difficult to work out how to undo the spring tabs to release the airbag. BTW, the slots on the mounting pins face inward which is the direction you move the spring arms to release the airbag.

When I went back to reinstall the switches, it only took 5 to 10 minutes to get them installed with about the same amount of time to button everything back up again.

You will need a selection of Torx drivers to get the screws out for the switches.

 

Yeah, when I repaired my clockspring it took a couple tries to find the right size screwdriver to hit the clips right. First few I tried were too small. Definitely need to look into this (if I can ever figure out my cold start issue of course, lol).

 

I've always had luck popping the airbag out with a very small (one might even say "tiny") flat head screwdriver. Works like a charm every time Working in a salvage yard though, I've had a lot of practice lol. You want a challenge, try to get the airbag out of the steering wheel of a new VW Jetta or Passat...