Looking for 6.2 diesel nerds

[66gmcguy]

Hello all, I made this account about 6 years ago but haven't really been on it until recently to post some square body parts for sale, and to get some technical help.

I just picked up a 1982 GMC K2500 with a 6.2 diesel engine. This is my first diesel engine, so I am still learning about them. I drove one hour with freeway, mountain, and city driving all on the way home and it seemed to be running great and make decent power. I went to go start it the evening after I got it home and lo and behold, it wouldn't even fire. I eventually got it fired the day after drove it around again (to introduce the dog to the new truck, because car rides in the back of trucks are his favorite thing, even more than eating.) I shut it off, and it started back up 2ish hours later, but the next day, I couldn't get it cranked, even after letting the batteries sit on the charger for a couple hours, and with the block heater plugged in (which I am unsure if it even works.) I decided to test the glow plugs with a test light, and sure enough, none of them worked, so I am going to replace them tomorrow. Is there anything else that might be causing this non-start issue that I should look for? When I crank it, smoke comes out of the exhaust, but it neve fires.

Also, I should mention, one of the previous owners installed a manual control for the glow plugs. Will this cause any issues? Also, what should I look out for as far as problematic components with these engines? I bought this truck with the intention of doing a gas engine swap, but I decided I liked the diesel too much to replace it just yet.