Light switch diagram

[needlenose]

Someone posted a diagram of the headlight switch a while ago. Does anyone remember what the topic was? I though it was something to do with wiring in relays for the headlights.

I'm wiring in coolant/boost/pyro gauges and I would like to tie into the existing cluster dimmer.

 

[needlenose]

Orange/Black

 

[franklin2]

You can tie into any blue/red wire under the dash. Blue/red leaves the switch and goes down to the instrument cluster fuse in the fuse box, and then leaves there still blue/red, and branches out to feed all the dash lights. If you wanted to use a fuse tap, you could tie in at the fuse. It varies with the dimmer down there also.

 

[franklin2]

Here's a diagram. It's called lightblue/red officially. And I was wrong, the diagram shows a white/lightblue going from the headlight switch to the fuse box.

http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=43852

 

[needlenose]

Thanks for the diagram.

Yeah, I found out the orange/black is wrong. It's weird. I probed the orange black with the truck turned off and the lights on. Turning the knob changes the voltage from about 3v-12v. So I assumed that was the dimmer output. I tied into it, but when I turn the ignition on, all the gauges light up. But if I turn the knob, they dim. So there's no way to turn them off.

I'll have to open it back up.

 

[madpogue]

^^^^^ That might be the radio display wire.

 

[franklin2]

Radio display uses the same lightblue/red wire. The whole dash uses it. The radio usually also has the brown running light wire going to it, that signals the digital display to dim when you turn the lights on. The lightblue/red goes to the button illumination.