I did find a few smaller leaks in the plastic hoses and replaced these. I tried and tried to get it started. I checked all the fuses and they all looked good. I also checked the fuse specifically for the pre glow circuit and the fuel pump and it looked good, but after running out of ideas I decided to put a new fuse in and it started up right away and the glow plug light came on.

I do not know why this happens. When I measured the resitance on the fuse that did not work it was very low indicating that the fuse had not burned, but it was not working. Maybe the contacts where not good or something, but a new fuse did it and there have been no problems.

I had a similar issue with on an 85 300D where i went crazy looking and looking and changing the fuse which looked good solved the problem.