Making this for the Early S198 Owners with the retro Steering wheels. Seeing as how the model is over 20 years old now pretty much all the LEDs are starting to dim or just burn out. This guide will go over completely replacing the LEDs in the cruise control buttons on the steering wheel. Here's what youll need.
- A complete Soldering Kit (Iron, Flux, Solder, Tweezers or side cutters, something to hold and move around the tiny LEDs)
- At least 5 (3528) LEDs that are the colour of your choosing, they'll measure around 3.5mm X 2.8mm (I would recommend buying more in case you accidentally lose or break them)
- 8mm Socket and ratchet
- Tiny Philips Screwdriver
- Tiny Flathead screwdriver and/or a prying tool of sorts
Youll want to go about as if your removing the Airbag. Disconnect the negative battery terminal and drain electricity in the car to prevent engaging the airbag. You'll want to pry two rubber circles around the steering column out of their holes using a pry tool. Inside youll see two 8 mm bolts, remove both of them. After youll be able to pull out the Airbag a bit but it will be connected to two cables. You can disconnect the cables from their respective sockets by squeezing the tabs on their sides and pulling them out though this is optional.
Depending on the model you might have a silver bezel cover just as I do over the panels of your steering wheel. Dont confuse this with the plastic panel itself, otherwise you may damage it. Use a prytool to pry under the plastic panel of the steering wheel and do one side at a time. Once removed it should look like this.
You may now pull up on the actual physical buttons to remove them though try not to damage the wires connected to them. Once removed you can press on a tab by the connector to disconnect it fully.
You should now have the entire button assembly for one side. Repeat this for the other side. If the Silver Bezel cover pops off the plastic trim you can just tack it back on using contact cement, It wont peel off again even in extreme heat. After taking both assemblies out you can now begin taking them apart. There will be clips on the side and a tiny philips screw retaining the assembly.
Take out the screw, and use a small flathead to wedge the assembly away from the clips to eventually remove the top from the bottom. Inside youll find the board, its membrane, some white pegs, and youll have the top and bottom outside assembly. DONT LOSE THE PEGS if you do the buttons wont work. Do the disassembly on a neat desk.
You can put everything to the side except the board and begin removal of the old LEDs. For reference id take a picture of the board prior to removing the LEDs so youll know where to solder the LEDS and their polarity. If you lose track of which side is which then youll spend more time on this than you need to. The process of soldering involves heating up the iron and placing it next to the connection of the old LEDs to remove them. Use tweezers or a pair of side cutters to hold them securely. Youll then need to prep the empty surface with flux and maybe a tack of solder to hold the new LED in to place. Use one hand to hold the LED with tweezers and solder the LED with the Iron in the other hand while making sure the LEDs polarity is properly alligned. You can tell which side is negative through the triangle on its corner. Once one side is tacked on you can solder the other side by feeding solder into the other side and touching the iron to it. Below youll see a space after removal (Red Circle) and a space after soldering (Blue Circle).
Once You Finish soldering all the LEDs you can place the membrane onto the LED side and place it back into the bottom assembly. Seal it by clicking the top assembly onto the bottom assembly.
Once both assemblies are done you can test if they work by reinstalling the airbag but feeding the button connections through their respective holes. Reconnect the negative terminal of the battery and connect BOTH Left & Right Assemblies to their wires and Turn on the headlamps of the car. If done correctly the LEDs on the buttons should turn on. (Both assemblies must be connected or the LEDs wont turn on, I couldn't tell you why but its probably just because of how the circuit works)
Heres me testing the boards without the plastic covers.
If all the LEDs work then your finished with the hard part. Just remove the airbag again and insert the button assemblies into the wheel. Insert the plastic Trim pieces for the buttons back on and reinstall the Airbag. Dont forget the rubber circle covers and you should be done. Should look like this.
This same process can be done with the entire car. I'm talking the HVAC Bezel, Climate Control, Locking Buttons, Window Switches. As long as the actual button works and its mechanics all youll need to do is remove the button/switch in a similar manner, disassemble the switch to access the board and solder the exact LED onto the board/circuit. Just make sure its the same LED so you wont have to mess with resistance bands and whatnot. Let me know if you want a post on doing the HVAC Bezel LEDs, Ive already done it as you can tell from the photos.
- A complete Soldering Kit (Iron, Flux, Solder, Tweezers or side cutters, something to hold and move around the tiny LEDs)
- At least 5 (3528) LEDs that are the colour of your choosing, they'll measure around 3.5mm X 2.8mm (I would recommend buying more in case you accidentally lose or break them)
- 8mm Socket and ratchet
- Tiny Philips Screwdriver
- Tiny Flathead screwdriver and/or a prying tool of sorts
Youll want to go about as if your removing the Airbag. Disconnect the negative battery terminal and drain electricity in the car to prevent engaging the airbag. You'll want to pry two rubber circles around the steering column out of their holes using a pry tool. Inside youll see two 8 mm bolts, remove both of them. After youll be able to pull out the Airbag a bit but it will be connected to two cables. You can disconnect the cables from their respective sockets by squeezing the tabs on their sides and pulling them out though this is optional.
Depending on the model you might have a silver bezel cover just as I do over the panels of your steering wheel. Dont confuse this with the plastic panel itself, otherwise you may damage it. Use a prytool to pry under the plastic panel of the steering wheel and do one side at a time. Once removed it should look like this.
You may now pull up on the actual physical buttons to remove them though try not to damage the wires connected to them. Once removed you can press on a tab by the connector to disconnect it fully.
You should now have the entire button assembly for one side. Repeat this for the other side. If the Silver Bezel cover pops off the plastic trim you can just tack it back on using contact cement, It wont peel off again even in extreme heat. After taking both assemblies out you can now begin taking them apart. There will be clips on the side and a tiny philips screw retaining the assembly.
Take out the screw, and use a small flathead to wedge the assembly away from the clips to eventually remove the top from the bottom. Inside youll find the board, its membrane, some white pegs, and youll have the top and bottom outside assembly. DONT LOSE THE PEGS if you do the buttons wont work. Do the disassembly on a neat desk.
You can put everything to the side except the board and begin removal of the old LEDs. For reference id take a picture of the board prior to removing the LEDs so youll know where to solder the LEDS and their polarity. If you lose track of which side is which then youll spend more time on this than you need to. The process of soldering involves heating up the iron and placing it next to the connection of the old LEDs to remove them. Use tweezers or a pair of side cutters to hold them securely. Youll then need to prep the empty surface with flux and maybe a tack of solder to hold the new LED in to place. Use one hand to hold the LED with tweezers and solder the LED with the Iron in the other hand while making sure the LEDs polarity is properly alligned. You can tell which side is negative through the triangle on its corner. Once one side is tacked on you can solder the other side by feeding solder into the other side and touching the iron to it. Below youll see a space after removal (Red Circle) and a space after soldering (Blue Circle).
Once You Finish soldering all the LEDs you can place the membrane onto the LED side and place it back into the bottom assembly. Seal it by clicking the top assembly onto the bottom assembly.
Once both assemblies are done you can test if they work by reinstalling the airbag but feeding the button connections through their respective holes. Reconnect the negative terminal of the battery and connect BOTH Left & Right Assemblies to their wires and Turn on the headlamps of the car. If done correctly the LEDs on the buttons should turn on. (Both assemblies must be connected or the LEDs wont turn on, I couldn't tell you why but its probably just because of how the circuit works)
Heres me testing the boards without the plastic covers.
If all the LEDs work then your finished with the hard part. Just remove the airbag again and insert the button assemblies into the wheel. Insert the plastic Trim pieces for the buttons back on and reinstall the Airbag. Dont forget the rubber circle covers and you should be done. Should look like this.
This same process can be done with the entire car. I'm talking the HVAC Bezel, Climate Control, Locking Buttons, Window Switches. As long as the actual button works and its mechanics all youll need to do is remove the button/switch in a similar manner, disassemble the switch to access the board and solder the exact LED onto the board/circuit. Just make sure its the same LED so you wont have to mess with resistance bands and whatnot. Let me know if you want a post on doing the HVAC Bezel LEDs, Ive already done it as you can tell from the photos.
