Hey Linc.
How is ALBQ. this new year?
I have to go there because I have bought a BENZ 300TD and hopefully pick it up soon(south of downtown ALBQ).
Maybe the problem with the glow plugs is NOT that the GP's are bad BUT the resistance at the pressure plugs/caps(like spark plug caps), is that there may be sufficient drainage/loss of contact to NOT let enough amperage build up.
Clean with
Radio Shack electric cleaner(small white spray), and see if that is what was, before getting into it any more.
Let me know IF you/him has to cut the GP harness and install another one, I have done mine and I CAN help with this "medical" procedure.
Get me his phone # 'cause I could not get it earlier.
Let me know, I hope to be able to help out...
PS. I know you can get a hold of a hangar/garage to have this forsaken GTG that you guys haven't had and
get it organizedeek
!