[Guide] Replace steering wheel and hvac light bulbs with LEDs

[crank]

Hey there,

today I fixed some lights in my steering wheel controls and in the HVAC control unit.
I want to share my experience with you and hope it will help others.

UPDATE: I don't recommend doing it without removing the steering wheel! See Post #6
It's almost impossible to get them back in this way

I think light bulbs are not as reliable as LEDs so I decided to replace the light bulbs with SMD LEDs. I ordered cyan colored 0603 LEDs on eBay which match the color of the light bulbs very well J

First I was trying to use an allen key to pull the controls out. I ended up using a medium sized flathead screwdriver. Just stick it into the bottom of the control and pry it out. Be careful the wires are very tight and you will not have much room to push on the release tabs of the connectors. Take your time.




I also removed the HVAC control unit and went up to my apartment.

First I took the steering wheel controls apart. Just use a flathead screwdriver to release the tabs. Then I investigated the polarity (in case you want to use replacement light bulbs it doesn’t matter)


(temp/vol control)
I soldered a 1.5k Ohm resistor in series with the led to the pads. I had to use 45° to fit both to the pads



After soldering the temp/volume control I went back to the car for a test


It worked and looked good so I went back up and soldered the other controls.
Here are the polarities marked for each control:

(seek/band/scan)


(accel/coarse)


(cruise on/off)

After finishing the solder job I secured the LEDs with some hotglue to be safe.

Here is how the control looked like after reassembly:






The steering wheel controls were done, so lets move on to the HVAC Module. I took it apart and went back to the car with my multimeter. After figuring out the polarities I desoldered the burned out light bulbs.

Here I marked the polarities.


This time I used 1k Ohm resistors in series with the led. Here is a picture of my first test run:





I hope this little “guide” is helpful for someone

 

[crank]

And here the reassembled unit:

 

[Homer Jay]

Nice work and helpful to document with pictures!

 

[CorvairGeek]

I really like the idea of using surface mounts. I never thought of using them because of the plastic light diffusers across the face in the radio. I felt I had to match the envelope size.



I tried the blue LEDs and then went with the clear and reinstalled the little blue/green covers. Another reason I was thinking of matching the envelope size. They are still actually more blue than original and the picture shows. The true white of the LEDs lack enough yellow light to make them match.

Between the DRLs and poor incandescent quality, it sad to have a car full of burned out bulbs that aren't readily replaceable.

 

[crank]

Nice work 👍
First I was thinking the same, using white 5mm LEDs and reuse these little blue condoms
but then I found these cyan colored smds on ebay. Unfortunately they are more blueish as well but I'm okay with that.

I think the best way to match the color is using really warm white LEDs around 2500k - 2700k and then use these condoms.

 

[crank]

Today was a real nightmare of a day for me 😒
I wanted to reinstall the controls to my steering wheel. It was pain in the ass to get them back in. I would say almost impossible because of the short wires. I tried every little tool I have lying around but nothing worked to get the connectors in.
Then I tried to remove the airbag with no luck. I found some posts that a screwdriver will do the job, but not for me. No movement at all.

I was about to give up but then I found a tricky way to get them back in. I disassembled the controls.
I put the lower plastic part in first and connected the plug. After that I put the pcb in and carefully the housing.
It is a little tricky because of these little red plastic pins. They are falling out all the time.
Here some pictures:



It took me almost 5 hours to get this job done !!! I don't recommend doing it and I will never do it again.

But here is the final result:

 

[JGBuick]

Today was a real nightmare of a day for me 😒
I wanted to reinstall the controls to my steering wheel. It was pain in the ass to get them back in. I would say almost impossible because of the short wires. I tried every little tool I have lying around but nothing worked to get the connectors in.
Then I tried to remove the airbag with no luck. I found some posts that a screwdriver will do the job, but not for me. No movement at all.

I was about to give up but then I found a tricky way to get them back in. I disassembled the controls.
I put the lower plastic part in first and connected the plug. After that I put the pcb in and carefully the housing.
It is a little tricky because of these little red plastic pins. They are falling out all the time.
Here some pictures:

View attachment 27088

It took me almost 5 hours to get this job done !!! I don't recommend doing it and I will never do it again.

But here is the final result:

View attachment 27089

Just found this post and wanted to thank you for the pictures! I was going to do this myself but am seriously reconsidering it! I'm fairly competent but this is craaazzzyyy. Your line "Never do it again" made me LOL! Great job.

 

[lilpoindexter]

SWEEET!!!

 

[Alan 55]

And here the reassembled unit:

View attachment 27062

Very helpful pictures and info. Thanks for sharing!