GM-GMC: Engine does not want to crank, delco remy, failure points

Question
Dear Sir, I have a GM 6.2l Diesel. I think it is a 1982 model.This beast does not want to crank over the engine at all when the engine has reached its working temp. Sometimes first thing in the mornings it will crank over fine, and sometimes it just does the same as when the engine is hot. It is a brand new starter motor(110 9563,Delco Remy USA)& battery. The contact points of the starter motor's solinoid keeps on burning and this aggrevates the starting. I have even taken out the glow plugs, it cranks like a dream with the glowplugs removed.

Please help, the only effective way of starting it, is by run starting it, it starts real easy then. Once it is going it runs like a dream.

Best Regards
Gustaf

Answer
GM's battery connections are known failure points on 6.2/6.5 diesels.

I suggest that you remove and clean all of the connections, including all the ground connections, in order to help with the problem.

Remember that a battery cable can corrode under its insulation and replace any such cables, or ones that are suspected as being bad.

Also, make sure that the starter is okay.  With the cables disconnected, take the starter to an auto parts store and get it tested.