There is a red/lightgreen that feeds the glowplug controller, that is the same red/lightgreen that feeds the injection pump. So if you can get it to run at all, you can assume that is good. It has a fusible link in the wiring(not sure of the exact location). That's the "brain" part of the glowplug system.
The "brain" feeds the power relay that sends power to the glowplugs. I believe the power relay is located on the pass side fender. It has a heavy red wire feeding one side of the power relay(input from the battery +). The output of the power relay feeds 3 smaller wires, all with fusible links very near the relay.
A. One wire has a darkblue fusible link, this wire feeds the light in the dash.
B. The other two wires both have green fusible links, and both of these wires feed the glowplugs, one feeds the left bank, one feeds the right bank of glowplugs(4 each).
