Final post on the tail light not lighting problem.
My final solution was to wrap the umbilical cord end that plugs into the jeep with electrical tape and I sprayed electrical contact cleaner in the holes. Although I don't think this will be a permanent fix and I eventually have to rewire a new receptacle on the jeep this seems to have snugged up the umbilical enough to make good contact.
Also during this process I discovered that the umbilical cord has a screw on each end that tightens and holds the outer casing of the wire into the connectors. On both ends these had come loose and needed to be tightened. Probably wouldn't hurt to make that a periodic check as it could prevent some trouble somewhere down the road.
Thanks again for all your suggestions and help.
04 HR Ambassador 38 PDQ ISC 330 Cummins,
09 Jeep Wrangler Sahara Unlimited,