Glow Plug System Problem

[Brogman]

I checked the voltage on the GP controller card connections, here are the readings I got.
Ignition switch off no voltage to connections: A,B,D,G,H,L,M
Ignition switch on:
A purple none
B light blue 12.6 volts
D dark blue none
G two wires pink and pink/black stripe 12.6 volts
H orange none
L yellow 12.6 volts
M two black wires 12.6 volts

Ignition switch to start:
A purple (the one I reconnected) 10.21 volts
Is this normal? Could my GP controller card have failed?
I have a New GPD-2B GP card that I put in and then applied powered to it but there was no green light on the card, so could this new card be bad?
I have not tried grounding the light blue wire to see if that will cause the New NAPA ST85 GP relay to work yet. I did jump the relay and it clicked I didn't see if it powered the glow plugs.
Any help by those of you who know this system well would be much appreciated.

 

[Brogman]

First I would like to thank "rsh4364" and "cucvrus" for responding to my post for help. I finally skinned the bear today thanks to all the incredible information many of you have placed here on this web site. The last problem was the ground wire on the right rear head that goes to the GP card and the fuse box had broken off at the connector and it retracted so it was close to the diagnostic plug on the wiring harness. I saw it but didn't know what it was for. Must have broken way back when I first started the rosscommon conversion and tried to fix the starter purple wire. Any way Thank YOU Steel Soldiers!