I have a 1985 golf diesel that won't start. I put new glow plugs in. and
a relay and still it won't start. Any suggestions to try?

Changed out fuel filter?

Yes the fuel filter was replaced as well as the glow plugs, and the glow plug relay. I
did a continuous start 3 times and felt the area around the glow plugs and it did not
warm up. Could it be the ignition switch?

Yes, ignition switch could be the fault but first, any other electrical issues? When did the non starting issue start?

I had a new switch put in about 4 months ago, but everything lights up on
the dash. the last time the glow plug light did not come on. Now is times its
self out. I pulled the first injecter line and nothing comes out. Is there a
pump in the fuel tank? The injector pump has only about 30,000 miles on it.
So I just don't know what to try next. Should I have someone turn the
motor over while I put fuel through the injector Pump. The injector pump
does not seem to be leaking fuel anywhere. I drove home. parked the car,
about 1 hour later started the car and moved it out of the driveway. went
out the next morning and it just wouldn't start. I have worked on it for
about 2 weeks now and can't get to the problem. thank you.