Today I took the GMC wiring harness I bought from the salvage yard and went through it with a fine tooth comb. The alternator connectors were all cut off, so I went to the parts store and bought replacements.
I was recently noticing how short the alternator wires were on the wiring harness that I had as a temporary one (off a 67 C10), and I did not want this problem with the new one, so I cut the necessary lengths off the junk harness that came with this truck and spliced them into this new one where someone had cut it at the junkyard. I added those flexible plastic wire protection tube things and installed this into the truck (after removing the 67 C10 wiring harness).
All of the headlights now work (all of them as opposed to only two of them with the C10 harness) but I still have no brake lights or rear lights yet.
And here is more electrical news. The dash lights went out yet again (GRRRRR!!), my hazard lights work perfectly, and all signal lights work for the first time since I owned the truck. The turn signal indicators have not worked in the dash gauge pod yet, so there is still some strange electrical gremlin that I must find. And when I turn on only the front amber lights (one click pull on the light switch) only one of the amber lights comes on. I know that 67s are wired so that the amber lights are NOT on when the headlights are, so I am not sure about this issue. I have a feeling that the long-awaited solution to the no brake/rear lights issue is just around the corner though.
