eBay Switch Dash Lighting Mod
Today I worked on a mod that'll be part of a larger project. Previously I purchased a set of
after-market factory style switches off eBay. They work well aside from feeling a bit cheaper than an OE switch, but they don't have any dash lighting bulbs, thus making the switches rather hard to see in the dark.
However, the housing is at least already somewhat made to support dash lighting, so I thought about it and figured out how to add an additional bulb into these after-market switches.
These switches already have a light for when the switch is enabled, it's a simple incandescent bulb soldered directly to the switch body. It looked like one would fit in the bottom of the housing as well. I found some
bulbs on DigiKey that matched the ones already installed.
I also needed to add an additional pin to each of the switches wiring pigtail; they only have 3 wires (12V, GND, and OUT), but the connector has an empty 4th slot.
I removed one of the pins from one of the harnesses and cross-checked it to figure out what type I needed to order; I found
these pins which ended up fitting perfectly.
A couple of mods to the switch housing and internals were needed before soldering the bulbs in.
First I drilled a new 1/16" hole for one of the legs of the bulb. This was because the leg comes close to the OUT portion of the switch on the inside, and I didn't want vibrations to inadvertently cause it to short, thus turning on whatever the switch is hooked up to.
Next there is a black plastic block (essentially it does the "switching") that requires some Dremeling on its bottom edge. This is to allow room for soldering the new bulb to the switch body. The edge lip is just Dremeled down flush with the rest of the block.
Then I fed the legs of the bulb through the body and soldered each side down to the switch body. One leg goes to GND, the other goes to the normally unused pin, which is now our dash lighting pin.
The switches were then reassembled;the process is the same as normal, aside from having to feed the black block in behind the new bulb, which is quite simple.
Next I set everything up for a test. The switches still worked as they did previously, but when the new blue wire was connected to 12V, they now featured dash lighting!
Switch on w/ no dash lighting (stock function):
Just with dash lighting, switch off:
And both dash lighting and switch turned on:
I tested this setup by leaving both bulbs on for about 90 minutes to see how hot the switches would get. They definitely got warm (125F was the hottest I saw), but didn't seem to be any hotter than the factory switches do, so I consider that a success!
Soon I will be embarking on building a fuse-box and reworking some of my previous under-hood wiring projects. I will also be wiring up my lockers at that time, incorporating them into the new fuse box. I wanted to get this switch mod done before I started that project.