Right tail-light issues: sometimes works and sometimes not?

My son's '93 Neon' right tail light works on and off. The left one has no problem. He has changed the fuse, checked the light itself. He was told it is probably electrical. Any suggestions on how and where to start checking? It seems obvious its something directly attached to that rear light. Signal and backup works on and off also. I think it's a loose wire, but have no idea where to look. Someone mentioned Dielictic Grease on another tail-light Q. Where is that found and would it affect only one light? Where is the Harness connector found? Thanks in advance.
Right tail-light issues: sometimes works and sometimes not?
It sounds to me like the right side has a grounding problem. Check to make sure which wire is the power (+) wire and trace the other wire if you can. This same wire goes to all the lights to complete the circuit. That would be the ground (-). If you can't trace it you can try putting a temporary jumper wire from it to a good metal area for a ground. Make sure it is not the power wire or you will blow a fuse and maybe cause more damage!!! Cars are grounded through the body so if it keeps working after that you know what the problem is. Then you just have fix the ground problem. It seems like it may be a bad wire in the wiring harness between the two sides. Good luck and Merry Christmas!!
Right tail-light issues: sometimes works and sometimes not?
Put a bulb in it even if it %26quot;looks%26quot; good.

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