2006 Hyundai Sonata Electrical Issue

We just bought a 2006 Hyundai Sonata. It is a very clean car. The battery was replaced by the previous owner in January 2010. We noticed within a few days of driving the car an issue where the headlights would dim and the radio would shut off with a pop (on any station) and turn right back on. The AC cut out during the same instant when it was on. We took the car in to the local dealer. They were able to duplicate the problem which occurred when going over a bump in the road or braking. They eventually were able to duplicate the problem in the stall.

The original diagnosis was that transmission fluid was leaking from one of the seals into the alternator. We paid to have everything pulled apart and replaced. They did a recheck after a few weeks to make sure nothing was leaking after the work that had been done. Everything looked good. A few days later, the problem returned. Again, the dealer was able to recreate the problem.

This time, it appeared that the electrical grounds were failing. The ground wires were grounded to painted surfaces so all of these were taped. We had the car a few days and no problems. Yesterday after sitting in the sun all day, we drove the car and the problem reoccurred.

Does anyone have any ideas or suggestions?

Take it back to the dealer and tell them to keep it until they fix it. I don’t know what they charged for the “previous fixes” that didn’t really fix the problem, but it sounds like they either owe you some money back or fix the problem!