I don't speak much electric, so I could use your guys's help on this issue. This is on a convertible, so no dome light, just driver's and passenger's floor 'courtesy lights.

The issue is both lights work, but only independently. Meaning, when I open the driver door, only the driver courtesy light comes on, -passenger side, only passenger side light comes on. When operating the light switch, only the drivers side light comes on. Any ideas what to look for?

My 2 cents for whatever it is worth. They are not wired together so that they both come on when one circuit "closes" My guess is if you trace the wires back you will find where you can join them. Probably under the dash, not in the engine compartment.

The switch is obviously wired into the dr side light as well.

Here is my copy of my wiring diagram. It may help.

Thanks Harold. I was messing with it and still no luck. As mentioned before, both floor lights work and are on, one at a time and work fine independently, but not together. The only way both sides come on is if both doors are open. They will not come on together when I open only one door, or switching on the dimmer control, then only the driver's side comes on.

Really could use some help, drives me nuts and I'm almost done with my restoration, so I wanna fire her up, but want everything to be perfect before I do. Thanks guys.

Power goes to the lights then to ground through the door jam switches. Power for the lights starts at the fuse box and tees off to the glove box lamp and the lighter then to the courtesy lamps. The grounds are also connected and teed together so if the driver door opens both lamps will light or if the passenger door opens both will light and if the rheostat grounds both will light. I'd say the connecting ground wire that goes from the passenger light and switch to the other grounding points is in an open state [not connected]. The power wires are connected or you wouldn't get the passenger light to illuminate and the passenger side door switch is grounding or the lamp would not illuminate but the wire that connects the passenger lamp to ground at the drivers switch or the rheostat is not connected.
Maybe someone rewired it in the past and did not connect the grounds or maybe the wire came loose at one of the junction terminals. Or maybe someone could not get the passenger lamp to operate and wired it independently from the rest of the circuit. The ground connector wires are white, on a 68 anyway I'm not sure about the 67 and 69.
Hope that helps some.

Man, your explanation really helps. I traced the wires and found one of the white wires routed through the driver's side kick panel disconnected. Looking at the schematic, that wire would connect to the dome light on a coupe, - since mine is a ragtop, I need to figure out where that wire connects to. If you have any info on this lemme know. Thanks again!

What year is your car?

I'm guessing 1968 based on his screen name? But that's just a hunch.

68 ragtop.

Finally found the problem thanks to your help. I ended up tracing the white wire and found a foot long section behind the instrument cluster that was bad. Cut it out and replaced that section and now the floor lighting works!!! Awesome! Thanks again for your detailed write up.

Duh, good point.