72 Sierra Grande wiring - still at it

[Bigblock50]

I'm still working on cleaning up the snarled wiring on my 72 GMC Sierra Grande. I discovered yesterday (on the glovebox label) that the truck has the "camper wiring" option which accounts for a lot of the spaghetti under the hood. The installation of the extra wiring is so poor I have to believe it was a dealer who tried to get it done. Some of the wiring matches the shop manual's "mobile home" diagrams, though the truck only had a slide-in camper.

Anyway, I reinstalled the main junction block wiring according to the circuit diagram and help from this forum, then gingerly hooked the circuit up. No disaster. With the key turned "Off", I got lights and horn as expected. With the key turned "ON" I got the blower motor and radio. Going to "Ignition" turned off the radio (OK) and unfortunately did not activate the solenoid/starter.

I have three leftover unconnected wires from the crazy quilt harness. First, a black wire, maybe 18 gauge, that APPEARS to be attached to the solenoid (very hard to see that) and was attached at the other end to a junction block mounted on the passenger side front fender. Then there are a pair of wires, blue and yellow, running together in wrapping tape that emerge from the cowl bundle near the heater blower and connected into the snarl of wires near the junction block.

Big question is why the ignition switch is not sending power to the solenoid and probably not to the HEI ignition module. Looking at that today, but testing ideas welcome.

Bill in Virginia