12 Volt Source?

[fordpwrstroke7]

I'm hooking up some LEDs in the bed of my truck. Does anyone know/remember which wire is a power wire? I found one that is blue w/ a white tracer but I don't want to cut it if it's not the right one.

I would prefer to be able to hook them up to my dome lights AND to a switch.

I searched for this but didn't see any threads or posts that said specifically which wire to use.

I do have upfitter switches. I guess what I'm asking is which is the power wire for the dome lights. It would be nice to have the option of dome or upfitter. When the truck isn't on, I'd use the dome and when it's on, I'd use the upfitter.

Thanks.

[tony97gt]

I just wired mine into the 3rd brake light. You can have the lights come on when the truck doors are opened, or you can use the dimmer switch next to the headlights to turn them on and keep them on. The wires I found at the 3rd brake light were a teal/blue one (no tracers if I remember correctly) and another color, along with black. The other color was for the 3rd brake light, so no use for that. The teal one was for the bed light.

[K1LLsW1TchEd]

You don't have to cut any wires if you don't want to.
Try this:
splice into the jacket or wire covering*I usually expose a 1-inch space of wire
solder the wire your adding into the existing wire
insulate and cover the connection with electrical tape

*I've upfitted over 300 Police,Fire and EMS vehicles so I've seen the best and worse work!

[fordpwrstroke7]

I got them hooked up to one of the upfitter switches. I'd like to also hook them up to the dome light dimmer on the dashboard to the left of the steering wheel.

Any insight on how to do this AND to be able to keep them hooked up to the upfitter? I want to be able to turn them on while driving at night and not have the interior lights on. Also, I would want to be able to turn them on without having to turn the key to position 3 so I'm not juicing the glow plugs and draining battery if the truck is not running.

Is this possible or do I have to pick one or the other? I already have them running on the upfitters.

[K1LLsW1TchEd]

You would need relays to hook it up to the dimmer and keep it on the upfitter switch panel and quite frankly the upfitter switch is your best bet. The interior dome light switch also activates the 3rd brake light spot lights so that is an option as well. Me personally, I would keep them on the upfitter switch.

**oh LED lights draw minimal amperage were talking half and single digit amperage draws!! so don't worry about affecting your cold cranking amps

[fordpwrstroke7]

Yeah, not concerned about them drawing power while on. I just don't want to have to keep the key in the position where the glow plugs are being lit up in order to have the bed lights on. Not sure if I'll ever be in a scenario where it'll matter but I want to have the flexibility to do what I want.

I've left my radio on all day with the sub kicking and the truck always starts right up. Again, not concerned about the power draw. Just want the ability to turn on the lights both ways.

I think I'll experiment tomorrow with the blue wire with the white tracer coming off of the actual dimmer switch on the dash.

[K1LLsW1TchEd]

Oh I'm sorry I see now, the upfitter switch is wired to the ignition. Run your lights to a constant 12volt source then. There are numerous 12v constant wires on these trucks.

[tony97gt]

Why not just use a multi meter to check the wire you are talking about for 12v when the dimmer switch is in the ON position?