The Glow plug solenoid / relay is mounted to the rear wall inside the control cube. You can find it in the TM.
There are 2 relay / solenoids mounted 1 above the other. One is the glow plug, but don't recall which, I think the bottom one.
There is no actual alternator, nor is there an alternator relay on an 003, just the fuse to the right of the oil filter and the DC voltage regulator behind it, inside the blower wheel enclosure. The Charging stator is mounted under the blower wheel and the rotor is inside the blower wheel itself.
Its all in the TM's, testing procedure is there as well as up in the sticky at the top of this Generator forum.