Glow plugs not staying on

A friend's 1989 F250 with a 7.3 IDI and a 5 speed manual trans won't start unless it's plugged in. When you turn the key on, the glow plugs only come on for about 2 seconds max when it's 30 degrees out. I'm thinking glow plug control module, anyone else concur?

the gpr and plugs need replaced. i would go with a stancor relay tho and ditch the stupid oem controler gp relay box.

Ok, thanks for the help. Direct replacement I presume? Just remove and replace the wires, not have to figure out how to do a whole new wiring schematic?