Hey Joe...need more help if you have time,
Here is the situation...I read the links you provided and it seems like I need to run a single speedo cable from the connection on the TC to the speedometer. I haven't done that yet.
To the tail lights...I got replacement tail light assemblies and am trying to install. There is a wire connector on the right frame rail just forward of the right rear shock (pictures below). Based on Coolermans thread #9
1974 fj40 taillight wiring help, the wires going into the connector are correct. The PO changed the wiring coming out though and I can't make the damn things work. The right tail light was somewhat in tact...the left he created 5 blue wires.
From that wire connector, there are 7 wires coming out (see pictures). 2 Green, 2 Red, 1 Black and 2 whitish yellow. I believe the 2 red to be the reverse light RB connection. The Green is the G for the running lights. One of the whitish/yellow goes to the right turn signal. The Black I believe goes to the left turn signal.
At the tail light connection for the right tail light, he has Green going to running light (one green wire comes out of this connection and heads to the right side running light on the side of the vehicle), red going to reverse light, whitish yellow going to the Brake terminal...and then he has a wire (whitish yellow) going from the brake terminal that goes over to the left tail light assembly. In the turn signal terminal, he has 1 wire going out and heading to the left tail light assembly.
Wires that go to the left tail light assembly side are red, black, green and whitish yellow. I think the Black is the turn signal, whitish is the GW for the brake, green for the running light and red for the reverse lights. If I connect the wires this way, nothing works. If I connect that whitish yellow wire from the right side to the brake light terminal, I get a right brake light...or just now I only get the left brake light. Then, it's a mess...sometimes I get a brake light and turn signal (on both sides...or just the right side, etc).
I feel like the right side is missing a turn signal coming from the connection? I have no idea what he is doing with the right turn signal wire that comes out of the right side turn signal connection, but it doesn't run up the vehicle. It seems like the brake lights will only illuminate if I connect the right whitish yellow wire to the left tail light assembly. WTF.
Right frame connector
Another picture of the same connection
7 wires coming out of the connection
Wires separate into right side, left side
Right tail light assembly connection