Me Again! Wiring problem on F1

[oneoldtruckguy]

Working on my 1950 Ford F1 almost everyday trying to get it on the road. Found this truck last spring sitting in a barn in Northeast Montana where it had sat for over 40 years. It had a very amateur frame off in 1984 and parked. I have got it running like a swiss watch (motor was done by old time flathead guy). Replace the master cylinder, wheel cylinders, hoses and several of the brake lines. Just put on a set of Reds Headers and waiting on Brockmans 12in steel packs. (Might be here today) Thought the Smitty's were to quiet for what I wanted. (thanks for everyone's help) Installed all NOS gauges. All new complete wiring. Truck runs good and drives good. Only driven about 5 miles so far. Now Here is my latest problem. Ordered a turn signal kit and installed yesterday. hooked it up like the instructions said. I hooked up the front first and they work perfect. Next ran the wires to the rear. got the left rear to blink but when I step on the brake the turn signals quit working. Only two wires come off the tail lights. (They are new also). I don't get how the turn signals will work when the rear tail lights are wired together. What am I doing wrong? Do I have the correct tail lights? Please give me some advice and Thanks for all Your Help so far.

Here is a picture of the truck if I can get it to load. Was painted in early eighties Mercury Marquis Gold. Hated it at first but now getting use to it. Its a 20 footer paint job. Truck came from the original owners who used it for a salesman's truck at their International Tractor dealership. They still have two more of their old dealership trucks. (one is another 50 F1)