86 escort diesel starting

Hello

I have this 86 Ford escort diesel.

I've replaced the starter for the second time. I also replaced both the
starter solenoid, and the "solenoid" on the firewall.

I drove the car for awhile, and left it parked for awhile. I came back
and it had enough juice to turn the glow plug lights on, but it
wouldn't click, or turn over.

I attached another battery and it turned over.

I think there's a short somewhere. Because I get 14volts when the
battery is being charged from the alternator.

THis car also has one of those cluth switches. It won't turn over
unless you press down on the clutch.

Any ideas. It seems I keep going through the same parts.