I'll check that fuse today.

Tim, I wasn’t sure what year vehicle you’re working on, but I may have missed it. I’ve attached a wiring diagram for a 59 car which I used when I was having a number of issues with taillights, brake lights and turn signals on my 59 F100. Hopefully it will help you to know which wires go where.
Looking at the diagram you’ve supplied, the colors seem to match up with the 59 wires, so Ford probably stayed consistent. For example, you said disconnecting the blue-orange wire caused only the front right turn signal to work. Blue-orange runs right rear turn signal/brake.
I won’t go into all of the unexplainable things I ran into over two weeks chasing the electrical issues. I did have a ground issue, a light bulb socket that wouldn’t light up because of worn-out contacts even though power was going to the socket, and lastly, a loose connection that kept the right taillight from illuminating. I don’t know if the car has a flasher, but that was keeping the turn signals from consistently working. All is good now. Let me know if you want any specifics.

Soffian Adam
Jamestown, NY
59 F100, 55 Club sedan

Or U may have a double filament Bulb with one Filament burnt out. I would replace all 4 Bulbs in Parking and Tail Lights with new known good Ones. See if that changes anything.

  

Tim, you don't happen t have a single contact bulb in the RH tail light, do you.  That would short the brake/turn wiring to the tail light wiring.

John - "The Hoosier Hurricane"

Everything worked perfectly in my 56. I removed everything I could for a body strip and paint. I tested as I went back together. The rear turn/brake acted crazy. I added a ground to everything and no better. I found a poor connection in the fuse holder going to the flasher. (One of the few fuses they have) After the connection was good everything worked perfectly. I didn’t need to fix any grounds...

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Did all that, will do again.
Thanks,
Tim

THANKS FOR YOUR HELP
TIM

In the dark recesses of my faulty memory I think I remember the front parking lights with brake lights being a fairly common problem. It seems that the "old guys" knew which wire to switch to fix it easily but no amount of checking or rewiring the connection has worked for me yet. At least the people in front of me know when my brakes are on!



Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

.Nothing worse than a "man made" wiring error.  It defies all logic.  I would start from scratch.  Disconnect all wiring and start putting it back,  one "leg" at a time'.  At each point, re check the function until the problem comes back.  

Double xcheck the junction block.  Some of the holes are connected to others and some are single.  A mix up might cause your problem.  Make sure you don't have the top and bottom confused.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ