You won't believe it but I found another soldier terminal hidden in there and I get a connection to the other side testing with the ohm meter when it goes into reverse. There is still no power but it looks like the switch is working for backup lights.
One wire appears to loop back onto the switch and I have the 2 extra screw terminals which is different to the picture you sent. Not sure what is going on there. As I mentioned it is very hard to see anything up there.

Ian,
See if this helps.
This is also from the same Electrical Book as before but shows the neutral safety switch.
They may have used two different switches, one without the back up wire connectors but I would doubt it.
Note on the diagram the two wires I have marked. If you have 4 wires off of the neutral safety switch then the two black ones not connected are for the back up lights. The other Blue-Red wires are already connected (or should be if someone has not bypassed it altogether which would be dangerous as it would start in P,R,N or D)
There is not a separate back up light switch as with the Standard and OD. It is all done with the neutral safety switch.
Check the power there in the black wires as before with the ignition on, lights on ad in reverse. If there is no power then the neutral safety switch is bad or the contacts are not aligning with the shifter in the Reverse position.
As Paul stated there "should" be connectors in the 14405 tail light assembly harness already.
Also look at "G" call out in the 1st diagram I posted.
Mine is a 56 with the back up assembly above the tail light but the wiring is the same.


Jim
Norfolk, VA

"MABLE"
1956 Thunderbird Green / Brown Interior (ZE-XG)

"MEAN GREEN"
1956 Mainline (FG-BE)

That is different to mine, is it 1957? From what I can see mine appears to have 3 soldered connections and 2 screw connections but it is impossible to have a good look where it is. I was trying to find a change in or out of reverse to be sure the switch will operate the lights but I can't detect any changes with the ohm meter. I'm wondering if it has been wired incorrectly. Getting power there won't be a problem, it is knowing how to wire the switch to make it work. I may have to take it out to inspect it properly.

Hi   just found this shifter with a switch that has 4 connections,  maybe you need a different switch altogether.     I'll clean it up and check the wire colors. B

Hi  I was looking at that same elec. drwg. ( reprint from T-bird supplier) last night looking for the proper connections. If you look again view "A". it shows taking power from that bundle in the center of the dash....."connect to existing double connector part of 14444 assy." As far as I could figure out ,that is the headlight wiring. I know...still not much help. I haven't yet been able to find a pic of the  wiring right at an auto trans switch. I'll keep looking. Black with a red tracer seems to be the wires you're after.   B

I have no power to any of the connections with lights on. I went over the switch with an ohm meter but could not find any change in or out of reverse. The only change I found was the two main screw terminals connect when it goes into neutral so now I'm very confused.

Still no power with the lights and ignition on. There are two wires under there that are black with a red trace but no power on either. It is difficult to get a good look under there but it does not look like factory connections so I'm starting to wonder if the fuse has been blown, where ever that might be. Unfortunately there is not a lot of room to see between the chassis and muffler. 

All the early Tbirds had the power wire going to the headlight switch then to the switch on the trans and then to the lights.  There should be two wires from the switch - one to power (the light switch) and the other going aft.

The wiring for the backup light is black with a red tracer.

The wires for the back lights is part of the 14405 assembly which is also the rear light assembly.  The proper wires may be included in the assembly but not hooked up.
As was already mentioned, the lights (either the parking or head) must be on for the back up lights to work.
One modification that Tbird owners do is taking the wire off the headlight switch and putting it on the ignition switch, giving you power either all the time or  putting it on an accessory terminal and getting power only when the ignition is on.

If you got an early bird (57) I recommend you get the 57 Thunderbird Electrical Assembly Manual.  It shows all the electrical systems, where/how  they are installed  and gives all the color codes.




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

Thanks, didn't think of that. I'll try with the lights on.

My back up lights on my 59 ford are wired through the neutral safety switch but it only has power to the back up lights when the headlights are on. Check it again with the car in reverse, the key on, and the headlights on.

John F

Ballwin, MO