I am installing heated seats in my 1988 SR5 4Runner and I have all the wiring sorted out (I think) except the switch illumination. The GREEN and BROWN wires on the switch are illumination positive and negative. I could tap into any number of locations to get the switch to illuminate but I would love to have the switch dim with the dimmer. Not that I will probably ever use the dimmer, but my goal is to make this as factory looking as possible, which is why I am using this switch from a 2008 Camry. Probably overkill but just seeing if anyone has any ideas.

 

According to the '89 EWD (which I believe came from JimKola), the dimmer rheostat pulls a R-B wire to ground. The nearest dimmer-controlled lamp might be the "power outlet" (oh, yeah, "cigarette lighter"). You'd connect one illumination wire from your switch to R-B and the other to battery (which is probably G).

A switch from a 2008 Camry is unlikely to have an LED, in which case polarity is not an issue. It wouldn't hurt to check, if for no other reason than to rule out a burned out incandescent bulb. If you do have an LED in that switch, I don't think dimming will work like you want.

 

That's perfect. Thanks! I do have an FSM but I don't really understand the wiring side of things. Looking at this though now it makes sense how it all works. I was able to plug my cig lighter back in and verify that it does in fact dim, so that would work great. Now the real question is do I make a little jumper harness between the factory harness and cig lighter so I don't have to splice any factory wiring. Hmmm....