Bob:

Your fuel pump relay should be located in the ice cube stack that is above the fuse holder in the passenger-side footwell. Remove the fuse cover door and you can just barely see the relays located above the fuses. You ned to carefully remove the kick panel to get access to the relays. Relay number 1 is for the fuel pump. Relay number 1 is the top left relay in the stack. There should be about 8-10 relays in all, four or five in a vertical stack on the left and another bunch stacked on the right. They are numbered in the harness, but generally the left ones are 1, 3, 5, and 7, from top to bottom, and the right column of relays is 2,4,6, 8. You may encounter another one or two relays mounted on a bracket screwed to the bulkhead so that they are positioned atop the main bunch of relays. If so, you will need to carefully remove the bracket to access the fuel pump relay, unless you have really small and nimble fingers.

FYI, your power window relay is likely mounted on the bracket in position 9 and the sunroof relay may be next to it in position 10. This info can be found in the electrical troubleshooting section for the 74 model, so it may not be 100% true for your 73, but it has been accurate so far for my 72SL.

The wiring information for the 72-73 cars is, IMHO, a weak link in the information chain. I suppose good mechanics have gone to MB schools and learned the ins and outs, but us poor folks who depend on manuals can feel like red-headed step-children at times.

You might want to pick up a CD ROM manual for your car from Mercedes Benz. They are pretty cheap from this factory site:

http://www.classictechlit.mbusa.com/MB/

Good luck with your project.

230/8