Thanks guys.

The pump is most likely original (and the car has about 240,000 miles). I've had the car for about two years and haven't changed the fuel filter.

I do have a 420SEL and a 190E sitting in my collection of cars ready to be fixed or used for parts. I'm thinking the pump from either of those should swap right out. Correct? That way I could test without having to buy a new pump. Or is there a way I can test my current pump?

If the problem is electrical, I might just start driving a different car. Oh man I dislike trying to find electrical problems.

Brett