Where to Find Brake Output Circuit of 2006 Ford F-150 with 4-Way

Updated 08/10/2020 | Published 10/08/2016

Question:

I have a 2006 ford f150 and I have already put the curt triflex inside the cab along with the adapter that plugged right into the factory plug. My truck already had a 4 prong outlet by the tow hitch that I can plug my boat into. I am wanting to tow another trailer with a 7 prong outlet and I bought the 4 to 7 pin adapter but I cant find a blue wire anywhere underneath my truck to connect to the blue wire on the adapter. Is it possible that it just wasnt wired for that, and if so, what do I have to do to be able to have trailer brakes on my truck? Thanks a ton!

asked by: Trevor

Expert Reply:

You have to look at the driver side frame rail for the wiring needed to connect to the blue wire of the # 30717 that you have. I attached a couple pictures that show what you are looking for.

expert reply by: Jameson C

click to enlarge

Tim

8/1/2020

Can I simply tap the black wire on the 7way adapter into the black wire I used to install the 4way harness since that runs directly to the car battery with an in-line fuse or do I need to run a new wire up to the car battery? What size fuse should I use?

Jon G.

8/10/2020

Good question! I would run a separate wire for your 12V pin on your 7-Way connector. This would keep the power for your trailer lights and the 12V power for your trailer on different circuits so that they don't interfere with each other. You're going to want to install a 40A Circuit Breaker # 9510 instead of a fuse.