i have a 2003 lincoln town car. I recently had a rear tail light assy replaced, and now, I have no running lights or high beam. What might the problem be?

Who knows what kind of fool worked on your car, I've met some that couldn't change a fuse without screwing up something. If your running lights and high beams worked before the guy touched your car but not after - then it isn't rocket science to figure out the answer to your question =YES

P.S. - and don't let him tell you otherwise!

Thanks for your support. I am in the middle of s 3 week discussion about their ( The body shop that did the work, which incidently is called " Accurate Collision ) responsibility. They claim there is no correlation between the work they did and the lights not working. I am in a dispute with the insurance Co ( GEICO) who are refusing to pay for the repairs.

I would have checked my fuses 1st, then any relays 2nd, 3rd I would get the bulb from the other taillight, swap test after visual confirmation that the filaments were NOT broken. 4th, I would check the wire connections on the part that was replaced. And if none of those work, i would look for a video that explains how to test your switch. Because your headlight high beam will have a fuse idependant from the fuse controlling your running lights. ( your lights may all run into a single relay under your hood though) It sounds more like a fuse issue