Left rear taillights not working (all the time) now. They used to come and go.
1.) Disassembled and checked continuity from each of the sockets back to the main plug area. Checked good, did not find a break.
2.) Checked power to the plug and find when I put a probe to the red wire and touch 2 of the others I get voltage. But, not all have voltage one to the other.
3.) When I plug the terminal to the board I do not get any voltage readings when I touch any of the socket copper contacts, nor from the terminal to any of the contacts.
4.) With the membrane plugged in I tried to gently 'massage' my way along to see if the thin film had a break that might show up when moved. Bulbs are good with continuity check.
5.) I know that I am largely ingnorant of electrical diagnostics - so maybe nothing I did from steps 1 - 4 bear any importance at all. What else should I attempt?

*Interestingly enough, I have brake lights and fog light on that bucket that works.