Hello everyone,

I want to wire up some lights in my cab to come on when my map lights come on. I have a 2016 Ford F-250. Any ideas on how best to approach this, I really don't want to have to pull my headliner down unless just absolutely necessary.

 

Welcome to the site..

Where in the cab do you want to put the add in lamps?

 

In the floor board under the glove box and steering column. I have the black carpet interior and I feel it will be nice to have some extra light down there at night when I open the doors or flip the switch

 

First....The 'switching' may be the draw back and would have to be done at the Map lamp unless you want to add in a separate panel or ? switch..


Second... The Dome and Map lighting current is supplied the BCM ( body control module) mounted in the right/passenger kick panel area. It's protected by a 10amp fuse.

Adding in a few or more incandescent bulbs may strain the circuit load and/or the Battery Saver Relay within the BCM. Certainly some overkill is written into the load carry of the relay, but the fuse may not be able to handle the extra load/s added in.

The Battery Saver Relay is 'non serviceable' unit, and any overload may not be what you want.

With all that said,, If you want the add in lamps to come ON with the Maps, it would have to be wired into the switch there. If the Dome lamp would work for switching (?), then it could be wired 'all' down low at the BCM. If the Map switch is preferred, you should be able to drop the lamp assembly remove the headliner trim/door seal (right side) and use a fish wire to push a trigger wire on through. Run the wire on down the removed roof post trim area and down towards the BCM.

Rather than wire it directly into the trucks system, adding a relay into the circuit may be a good choice. A small Solid State relay used (given they draw 'very little' current) over a mechanical coil type shouldn't stress the switch/ fuse/ BCM when used as a trigger voltage for the electronic type relay.
Using the wire from the Map switch to trigger the relay ON/ OFF and a simple ground from relay to chassis, then a load connection supplied to the relay terminal for the bulbs or LEDs. Lastly, a circuit protected wire connection to the relay for the combined added on lamps made..

Wouldn't be a huge task, and if you need any detail as far as wiring, component removal, let me know