I am using the daystar vent switch panel with the daystar lighted switches. One switch is powering the AC clutch for OBA. The other is going to be for high idle. But that only requires a wire to be grounded. I would like the switch to light up though. How could I wire this thing so that it lights up.

 

If the switch requies a positive flow through for led illumination, you could wire it that way and have it activate a relay that will pass through ground when energized. That's a bit of extra wiring, but without knowing the schematic of the switch that's what I would suggest.

 

So in the picture I uploaded I would make the

Blue: go to chassis ground

Yellow: to the high idle wire (that needs to be grounded)

Red: would stay ground as it is

Black: would be a positive from my switch

 

Actually, assuming you are using a "standard" 30-40 amp aftermarket automotive relay:

Terminals 85 and 86 energize the coil that triggers the relay, so you need a ground on one and positive on the other, doesn't really matter which is which. Terminal 30 is the input that you want to pass through (either ground or positive. Terminal 30 passes through to terminal 87a when the relay is NOT energized, and terminal 87 when it IS energized. So, you want the ground that you are trying to pass through to your high idle wire to come in the relay through terminal 30, and go out through terminal 87.

In short, the relay provides a a switched pathway for your ground feed, but provides no power or ground to your switch. You can pull + and - for the switch from elsewhere, such as the auxiliary power outlet wiring behind the dash:

Terminal 85 and 30 (blue and red in your pic) attached to ground.
Terminal 86 (black in your pic) to + output from switch.
Terminal 87 (the top yellow one in your pic) would go to your high idle wire that requires ground.
Terminal 87a (the lower yellow in your pic) is not used.

 

If you're talking about wiring a switch for the extended idle you don't need a relay. The ground pickup is only a signal, with very low amperage that wouldn't justify using a relay. Run a ground to the input of your switch and an output to Pin12 of the ECU plug. Run an ignition 12v+ to the bulb to power it, the switch should use one of the grounds.

 

You're correct. The circuit does not pull enough amperage to require a relay.

The problem is that the switch he is using requires a positive input/output to facilitate the illumination of the switch's built-in led lighting. If the switch's lighting were not LED (which is polarity dependent) and was a standard incandescent bulb, he'd have more options. That's why I suggested a relay. It's not needed for the high idle feed, but because he is stuck with having to have a switch output that is positive, we have a relay in there to facilitate a "switched" ground output.

I agree it's a pain to have to wire up a relay for this, but it will give him what he needs.

 

Right, but do they even make those switches with an LED? I've tried to find them because the switch can get hot to the touch with that incandescent bulb...

 

I used the relay method to be safe. It's all hooked up and working. Orange is extended idle and blue is OBA.