wiring a 3rd brake light on Cap?

[Bill's Dad]

I have a FS and a SS truck. This pertains to my 94 S10. I have yet to find the answer....I wired it into rear tailight and of course it flashes with turn signal, some say a "module"thingy they use at Cap Installation shops others say tap the CHMSL (center high mount stop light)circuit. I think it's a lt blue wire? but where is it?

[GreaseDog]

everything should run the length of the truck in the same wiring harness, trace it back from the taillights, tap into it, drill a hole in the base rail of the cap directly over the stake pocket, and run the wire up the bed, through the stake pocket, and into the cap.

[puma]

Most cap manufacturers supply a module with the light to allow universal connection to all trucks. This means you can just pull off the brake light circuit.

[Bill's Dad]

Thanks all, found it-was a yellow wire right down at the taillights harness...go figure? Geez, it's never this easy

[Canuck-Z71]

I had that same problem on my '92 S-10. I eventually ran a wire all the way underneath, through the firewall, and tapped into the brake light switch. When I got a 2000 GMC Sonoma, it came with the blue HMCL wire tucked underneath the frame rail, so I just spliced the wires together.