problem solved. the trunk latch has several places to influence the lights, a small micro switch that has a plastic slider on it and in the trunk latch assemble there is a plastic part that activiates this switch when the trunk is opened...that plastic non fixable sealed in the trunk latch is the problem, it's broken or worn out. so a new old ebay latch is coming for $22.00 . the latch by the way has a FORD stamp on it and it's not the Ford or Lincoln part as it does not include the plastic switch, although the numbers are simular and it would work if you had the plastic micro switch assemble to add to it. thanks to all of you.

 

I have same problem. Voltage on sockets until bulb, either side, is plugged in. Can anyone advise what to check?

 

I posted the original problem description. I solved it by replacing the micro switch that is located next to the trunk latch. (actually it is part of the latch assembly that secures the trunk lid when closed). Once the switch was replaced, the trunk lights worked fine.

 

As odd as it seemed to have voltage at the sockets yet no light, the switch was the problem. Thanks. The black plastic switch can be very carefully disassembled by removing the side facing the latch. Inside is a slide coming from the latch that depresses a plunger to keep the normally open circuit open. The problem is the plunger has lost its springing action or sticks as the slide pulls back to allow the circuit to close when the lid is opened. Working that plunger with a little WD-40 got it going again. Put it into the small black rectangular switch holder and snap the side back on. I'll find out how long it lasts.

 

here is when i gave up, replaced entire latch, all micro switch stuff working, lights do not work, no current to either light bulb, i gave up. thanks for the input i know every step you went through, it's real rube goldberg stuff and it works...just not mine