Hello all,

I've got a 2022 F550 that I ordered with no CHMSL. It just had a black plastic block-off plate covering the hole. I've now added the factory FL3Z-13A613-C (non-camera) third brake light. I also added the required LC3Z-14A411-E harness as well as the FL3Z-11654-CB headlight switch assembly that has the button for the cargo light.

The third brake light works when i press the brake pedal, but of course the cargo lights do not. I figured that would ve the case since, according to the internet, the BCM controlls the cargo lights. I made an appointment at the dealership to have them make the needed adjustments.

After an hour and a half with the truck, they said there is no way to do this, and that I was out of luck.

what are my options? Ive seen other threads where people add the camera-style CHMSL and then somehow edit the BCM to make it all work. My only other idea is to trace the wire from the lights back to the bcm, cut it, and run it to one of the two remaining Aux switches I have.

-Thanks

 

CHMSL means Center High Mounted Stop Light in case there are people like me who do not know what it is.

How do you want the cargo lights to work? Since you will have to wire them yourself, you have the freedom to do what you want. I remember on my old 1980, it had a factory cargo light, and the only way to make it come on was to turn the headlight switch **** all the way till it clicked. The interior light would come on all the time, but the cargo light would also. That was the only way to make it come on.

Do you want them to come on when you open the door? Do you want a special switch to make them come on like you mentioned? How did the factory have it that year? If you hook them into one of the upfitter switches, it will only come on with the key on. This will eliminate the danger of forgetting them and leaving them on accidentally and running the battery down. But may not be as useful.

 

Hi Franklin2,

Ideally I'd like them to come on when the cargo light button next to the headlight dial is pressed. The button is in a great spot to access when standing outside the cab. Thats why I'd like to make it work through the bcm as intended. I could wire it to the aux switch, but would prefer not to.

Some threads I have found suggest that I would need to buy a new BCM and have it configured, as an existing BCM cannot be reprogrammed. Im not sure if that only applies to older vehicles though. Honestly though, i would buy a new BCM if I was sure it would fix the issue.

It's just frustrating that all the hardware is there, and it's a factory option, but something is preventing it from functioning.

Any help is appreciated.

 

This is all I can find. Lots of useful info in this link for your chassis/cab truck, but I do not see a cargo light function, just a 3rd brakelight function. What I was looking at was page 126 in this link.

file:///C:/Users/Dana/Downloads/230750096634MYSuperduty3RFSC000000-BBLB.pdf

 

i would find the wire out of the switch pigtail that gets power when the cargo light switch is pressed.
run that wire to a separate relay to use as a trigger wire to turn the relay on. power into the relay from a fused wire direct to battery, and wire out of relay to lights.