It's possible the '82 is different, but on the ones I have worked on the dash light is in parallel with the glow plugs. If the dash light is on then the glow plugs have power.
I think the '82 has the fender mounted relay, so it should be pretty easy to check with a test light or meter. Maybe the dash light isn't wired right and is connected to some other power...
Regarding the fuel - like any troubleshooting, "divide and conquer". If the pump runs, then see if there is fuel getting to it. Or try putting the pump input hose into a jug of fuel to see if the rest is okay. On a new-to-you engine, almost anything is suspect - clogged tank screen, plugged/crimped line, air leak in the line, plugged filter, etc.
A couple 6.2L, 1985 2500 GMC Suburban and 1987 1500 Suburban
A few diesel W123 Mercedes
Gasoline lawnmowers and chainsaws