bfever74

I hate that I can't turn on my cargo lamp without the dome light. Completely worthless at night if I want to see if junk in my truck bed is still there while driving. Does this drive anyone else bonkers?

I'll feel like a complete idiot if there is a way to turn it on without the dome lights. Please enlighten me if that is the case.

Thanks

dsg2003mach1

if theres a way to do it you arent alone, I dunno it either. Its a pain the in the butt for sure, normally Id just leave the door ajar but not when its raining

safetykiller

My old Silverado had a it's own switch for a cargo lamp... Didn't realize the F-150 dome and cargo are the same.

11screw50

My nissan had a separate switch too, one of a few things I miss (one other big one is the utilitrack system, way better than Toyota's, I had some custom fork mounts for mountain bikes and a couple ammo boxes for storage...anything for unistrut fit the track).

BCMIF150

Slightly off topic, but I would suggest securing items in the bed if you are afraid they are going to come out from driving.

KJB13

My 2010 has a 3 position switch on the dome light. One of the positions kills the dome light but the cargo light will still work.

Theocoog

It is absolutely amazing Ford didn't provide this capability. But it's a great idea for a mod!

[MENTION=139427]bfever74[/MENTION] - Thanks for the idea!

This doesn't sound too hard, in theory anyway. You could splice a relay into the circuit that powers the cargo light so that it operates normally (with the dome lights) and also with a separate switch.

Now that I've thought about it, here are two ways of doing it that I can think of. There may be complications if the dome and cargo share the same power lead. Wiring gurus, please comment on these approaches:

Option 1

With a Bosch-type automotive 4-pin normally open relay, make the following connections:

Relay Pin 30 – Connect directly to battery or other constant 12V power to provide power to the relay for the light, protected by 10A fuse. Maybe a 5A fuse?
Relay Pin 87 – Run a wire from this pin to a splice (I like Positaps) into the power wire to the cargo light. This wire will provide power from the relay to the Cargo light. The light should also illuminate normally
Relay Pin 85 - Relay to ground.
Relay Pin 86 – Trigger wire. Connect this to a new, separately powered switch in the cab. Turn the switch on and the cargo light illuminates.

Option 2 – more complicated

Cut the power wire going into the cargo light. Then with a Bosch-type automotive 5-pin relay, make the following connections:

Relay Pin 30 – Connect directly to battery or other constant 12V power to provide power to the relay for the light, protected by 10A fuse. Maybe a 5A fuse?
Relay Pin 87 – Connect one end of the cut wire (the end that runs to the light). This wire will provide power from the relay to the Cargo light.
Relay Pin 86 - Relay to ground.
Relay Pin 85 – Trigger wire #1. Connect the other end of the cut wire (the end that runs back to the switches. This will trigger the cargo light for normal operation - when the dome light goes on, the cargo light goes on as usual.
Relay Pin 87a – Trigger wire #2. Run a new trigger wire from a new, separately powered switch in the cab to this pin. When the switch is closed, this wire energizes the relay and the cargo lights go on.

Time to dig out the wiring diagrams and start poking around under that dome light fixture...

mamonti

If you want to do this mod you can do it without a relay as the problem will come into play with how the system works! Normally you would have a wire going to the cargo light (dome light also if it was one circuit) from the switch. The system doesn't work like that as you will see below!

mamonti

The switch supplies power to the SCCM which then sends it to the BCM! It is VERY IMPORTANT that you never feed a + or _ into any of the switches, Modules (SCCM) or Power distribution Module (BCM)
So this is how you can do it if you want to have it work as it does OEM and as a stand alone cargo light! Are you interested????

mamonti

Well I guess I will continue in light (no pun intended) that someone might want to do this! The safe way of doing wiring mods when it comes to possible feedback to switches and modules is to use a diode. In case you don't know what a diode does, it only allows current to go in one direction. So here is a diagram to show what to do...



First you can cut this wire any where in the circuit so either as I show here or further up the line to the cargo light. The other two (exterior mirror) are puddle lights, if you have them, they are little lights under the mirror that come on when you open the door. If you have them this mod will not affect them as with it not affect the cargo light or interior lights from working as they do now.

Next where you cut the wire you solder in a diode. Notice I put a little arrow on the diode that is the direction current can pass. so it is important to have it pointed at the switch side and not the BCM.

Now splice a wire between the diode and the rocker (or what ever switch you want) and then attach it to one pole of the switch.

Last you get a power + ( constant) supply wire and attach it to the other pole of the switch. Of course make sure you tape any and all solder and spice joints.

There you have it! the switch will turn on the cargo light ( and puddles) and not the interior lights! since you got a constant + you don't have to have the key on. Now turn the switch off and open the door and the cargo light, puddle and interior lights will come on. Close the door and in a few seconds they will all go off. Last try the OEM switch as you always had to and you will see it works just like it always did!