Headlights dim jiggle then bright

HI all,

I am almost afraid to post this question.

My headlights, either one, will sometime be bright and fine and sometimes will dim. I get out of the car, pop the hood, jiggle the assembly and wiring and then bright again. I could understand one side, but not both.

My trunk light failed last year and now my reading light has just failed (I hope it's only bulb) trunk light is not bulb or switch.

Could there be or is there a history of underlying wiring harness problems with this car 1992 300e 2.6? I've read about disintegrating harnesses, I hope it's not my car.

Any thoughts would be greatly appreciated.

PS> Both headlight bulbs recently replaced.

Thanks,
Joel