Need a hot for roof marker lamps - will this work?

[DeadheadNM]

I’ve got all the pieces I need to install optional GM roof marker lamps in my 99 suburban. For this year, the dash harness connection is supposedly buried deep inside the dash. I’ve not been able to confirm where it’s located.

Therefore I’m contemplating a “plan B” for powering the lamp harness and am wondering if the following idea is reasonable. I’d like to splice the harness hot wire (brown?) with a supply wire at the headlight switch. Seem reasonable if I can identify which wire is hot when the running lights are on?

[Richard]

Tapping the running light circuit seems logical. Add up wattage of all roof marker bulbs. Watts/volts=amps. If worried about added load just put roof markers on a relay and power the relay with the running light circuit. Tapping at the marker may prove easier if you do not want to trace the circuit.
Edit- You may be able to put your HL switch in the park lamp position and check for continuity between red wire and others. That should show which wire is hot for the park/running light circuit.

[DeadheadNM]

Thanks for the reply. I appreciate the advice. The bulbs are style 194 3.78 Watts 0.27 amps total five bulbs. I could substitute LED bulbs for the incandescent examples now in hand.

I’ve located a helpful schematic for the switch that indicates the brown wire is that for the parking lights. So, it looks like a brown to brown wire splice would be the way to go and ground out the black harness wire. I’ll still hunt for the appropriate harness connector and splice as a last resort.

[Richard]

About 1.5 amps total for the load. I would not worry about adding the lights to the circuit. Good luck finding the connector. I would be looking for it myself as well, just in case it is there.

[DeadheadNM]

Great. Thanks again. I’ll post back when I complete the project.