My right rear door courtesy light has two wires- a solid red and a black w/ white stripe. What puzzles me is that both wires have voltage across them when the key is turned to the left or right. To me the red is the feed and black would go to the door jamb switch. I currently do not have a bulb in the socket- there never was one in place. None of the courtesy lights in the door pull handles worked in any of the doors when I bought it. I got the right front fixed after splicing the red and blk w/white wires which were severed in the door jamb. The right front now comes on when I open either of the front doors, telling me the front door jamb switches are good. I still have to splice those two wires in the left front door jamb which are severed, but not shorted. I have a '63 Sedan DeVille, 6339. The schematics in the manual are somewhat helpful, but the color coding doesn't match with what I have( pages 12-93, 16-104, 16-118 ). I should state that my wiring is still encased in the cloth tape so I know it's stock, also, the wires are not damaged in the rear right door jamb.Why do I have power (12V) on BOTH the red and black? I'm not putting a bulb in there until I fix it right. This is driving me up the wall.

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Little clarification would help to diagnose. You wrote that you got the right front fixed after" splicing the red and blk/white tracer wires which were severed in the door jam"  Did you splice them to each other?

Tom- the wires that were severed in the door jam, was from the repeated opening and closing of the door. I spliced the red to red and the black to black.

All of the courtesy lights in the circuit are tied together, so that if one switch is closed, they all come on.  
Therefore, it's a series circuit.  The black wire has power because the voltage is travelling thru all of the bulbs in series, it doesn't mean that it will come on.   If you take ALL of the bulbs out of ALL of the courtesy lights, then the black wire should show nothing, no voltage, no ground, but with bulbs installed, this is normal. 
Try installing the bulb. 

Mark- I just tried installing the bulb and it did not light up. I know the bulb is good- I tested it. My door skin is off so I have the wrapped wire harness just hanging  in the open. If I stick the bulb in one side of the socket that is connected to the red wire and touch the other end of the  bulb to ground, it lights up bright. If the bulb is connected to only the black wire, when I touch the bulb to ground- it appears to be off, but if I wait 5 seconds, the filament will start to glow a dim orange. Both read 12V, but the red wire must have more current through it to light the bulb brightly.This test only work with the key turned either ACC or IGN. Opening of the door didn't produce anything for me.

Andy, I have a 64 convertible and have checked ou all the courtesy lights on our to get them working. Here is what I found and maybe it will help you.

The courtesy lights are designed (convertible for sure) so that they will light when the door(s) are opened, when the light switch is turned to far left, or if a rear switch is used. They did this by running a RED hot wire from the battery to one side of each of the bulb socket--so one side of each bulb has 12v connected to it(hot side). The other side of each bulb socket is the ground side--and that side should NOT be hot. The ground side( blk/white tracer)  gets its ground from the pillar switch when a door is opened, when the light switch is turned to far left or the courtesy switch is in ON position.

 SOO it sounds like the GROUND side of your light socket is incorrectly tied to a 12v battery source somewhere in the wiring. Follow the blk/white tracer wire and find where it ties to a RED wire. I would also check  the Pillar door switch(s) as it should have ONLY ground wires on it.

PS . The red wire from the battery to each of the courtesy light sockets are ALWAYS HOT, so that when a door is opened they light up from a ground connection made at the pillar plunger switch(s).   

The wires chaff at the C pillar. Many times when I remove the wires from a parts car, the C pillar wires to the courtesy lights are chaffed through.  Take the back seat out and remove the wires.

I would first look at the kick panel area to find a possible solution.

Russ- I only have the courtesy light in the doors, not in the C-pillar by the rear passenger's head. I guess I should mention that the switch on the rear of the front seat is broken- someone's knee must've taken it out, but that shouldn't cause my problem.

Thanks Tom, that's what I was thinking. will check

The bulb the filament starts to glow after 5 seconds is that 12v is on BOTH sides of it.

One ,(RED wire) which is correct and the other side(blk/white tracer)which is incorrect.

You have proved that the RED wire presents a solid 12V to the socket, whereas the Blk/white tracer IS NOT presenting a good ground to the socket.

BLK/White is the incorrect side-- IT NEEDS TO BE A GOOD GROUND.

Tom- The 12v is on both sides of the courtesy light with the bulb removed.I would agree that the red wire is the feed wire and should be the only one with the 12V. It just puzzled me why I have 12V on the black/white tracer wire. I would assume that the back doors work the same as the front doors, in which it wouldn't matter which rear door I open- both rear doors should light up together. I haven't yet tore into the left rear door yet to see if there's an issue there that may be crossing over. Maybe it's where the rear of the front seat switch ties in- not sure yet as to where that might be. some more searching on my part. My guess then is that a 12V wire (red) is rubbed through and making contact with the black/white wire. The dim glow of the filament then must be telling me that the12V is being dissipated throughout the ground of this circuit.

From what I learned on our 64 Convertible. The RED is definitely the wire that is the one correctly  12V(hot).

You need  to find where that blk/white wire, that should be a ground,  is touching a positive wire. The wire bundle in the door hinge area(s) are notorious for cracked/broken OLD wires. The door plunger switches and around them,  are worth checking to, as they should have only "ground wires" on their terminals. Inside the door panels its a pair of wires going to the courtesy light(s) themselves-one is for 12V battery the other to be the ground.

 I had this same problem years ago with my 63 6339 . Had 12v to both wires in the rear door courtesy light socket. I found that the red and black/white wires had chafed together at the lower driver side seat area going to the switch on the front seat back . It's pretty tight fit thru there, maybe check that . My bulbs would blow first time opening any door, but would not blow the fuse. HTH



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