7way round pin to RV flat

You can't add a pressure switch, you need an air to electric brake converter.

Read this ...https://www.etrailer.com/question-45209.html

Don't try to add a socket or change it just get this ..

https://www.etrailer.com/Wiring/Pollak/PK12-724.html

 

I put a female trailer socket on my cat walk next to the pogo-stick to plug in my trailer cord. Ran a new 7 wire cord to the rv 7 pin to the rear next to my bumper pull hitch that way it is not wired directly into the truck and it is dead when not connected. Wired black wire only for trailer lights. I used blue wire for the acc battery power to trailer.
I wired in a Tekonsha controller that will even work seperately with the Johnson bar.

 

To clarify. The Tekonsha controller also works normally with the foot pedal too. Just wired it to the brake light switches to work just like in a pickup truck.

 

It’s a ‘67. Yes. I wired the blue straight to the 12v power source on starter lug for main battery cables with an inline Buss type 30 amp circuit breaker to allow me to hook abs trailers and so I can use it to charge battery on trailers through it. Had to add that because they do not exist on the pre-abs trucks. Some guys add an extra toggle on the dash to kill power through it when not needed or to turn on to keep the abs light off on newer trailers. The original wires to brake light switches were 14 gauge so I changed them to 12 ga. Overkill. With led brake lights they arn’t drawing enough amps to hurt the switches. Look at the small ga wires they run on the brake light switches on the pickups with all the factory tow package so that tells me amp draw isn’t all that much. And besides you technically got 3 wires controlling the brake lights 2 through the turn signal switch to both turns and the single dedicated red wire for the “fail safe”.

 

You look @ this. Pricey, but we'll made. JACKALOPEE | Szmyt ET Products

 

You look @ this. Pricey, but we'll made. JACKALOPEE | Szmyt ET Products

 

I have an 04 387 Peterbilt that I have for recreational use. Retirement toy. I used the commercial harness and wired a round female recreational 7 connector to the Pete. The plug-in also has the four/five flat adapter, so I can pull any trailer I want. I have one trailer with electric brakes, so I plumbed in an online switch for the brake controller. I do not like electrical issues, but I did get this working and it's very well...so far