I read through several posts here about this and I see theres a specific wire Ford put in to do this. I didnt see one for my Pickup in paticular and just wanted to see if anyone has done this and could direct me to the right spot. Some said theirs was in the engine compartment adn others under the drivers side door. I have a 1999 F250 SD Crew Cab. Thanks.

 

Of course there's a specific wire for the CMHSL. Otherwise, it wouldn't work. Generally, it comes off the brake pedal switch, then splits to the CHMSL and the MFS, perhaps elsewhere.

What, exactly, are you trying to do or learn?

 

Most of the older trucks ran this wire down the driver's side under the sill plate, and then up the rear driver's side corner of the cab. They swapped the location of the fuse box to the other side on the later trucks, so it might run along the passenger side sill plate. You can check Autozone's site under repair guides, and see if they have a wiring location illustration. They might not on a 99 model, but I know they do on the later models.

 

I bought a topper and I'm trying to hook up the Third Brake light on the topper. From what I have gathered reading here its a green wire but seems to be in various locations depending on year of truck. I was hoping someone here could direct me to the spot whos already done this. If not I have a few places to look and Ill track it down. Appreciate the help.

 

Thanks Franklin I'll check that out. Appreciate it.