Thanks mosesburb, I'll be sure to have a look at that.
I found some exciting pieces of wiring today. I've been shuffling things around between storage units, consolidating and getting ready to move when I find a new job. On one trip I completely filled the inside of the Suburban with stuff. I had removed the third seat and in the back I piled boxes to the roof, filled the two remaining seats with items and stacked up boxes over every inch of the floor too. With perhaps 1000 extra pound of dishes, appliances, books, auto parts, paperwork, computers and other miscellany, the Suburban didn't handle or behave any differently at all. The big block's torque smoothly pulled everything along as if nothing had changed. I remember being able to feel the difference in acceleration when I had more than one passenger with me back in the days when the Suburban sported a SBC.
While sorting, I came across two boxes of miscellaneous bolts as well as other automotive bits and bobs. I brought them home to separate out whatever was useful. Later, while checking them out, I spied a late model brake switch in one of the boxes. I pulled it out and there was a wiring harness attached.
Once I spied the oval weatherpack connector it was clear that this had come from my grandfather's truck. This is the cruise control harness that I had assumed was lost forever. The blue connector on the right hooks up to the cruise control motor, the orange one attaches to the mystery connector (mystery solved now) in my exiting wiring harness, the brake switch wiring is obvious and the other four wires are for the cruise control switch on the stalk. All I have to do is mount the motor (I've had it sitting on my bench for months), connect the two brake switch wires to a 1970 style four prong brake/cruise disengage switch (which I happen to already have), buy a period correct cruise engage stalk and wire it properly. Then the Suburban will have working cruise control.
Deeper in the box I found one more bit of wiring.
It is the missing Hot Fuel Module. This one plugs into the existing wiring harness and keeps the fuel pump on for 20 seconds instead of just 2 when the key is turned to the 'on' position. That's supposed to help alleviate vapor lock on hot days when the motor is already up to operating temperature, but has been shut off. It cycles fuel through the lines to flush out any that had boiled before you start the vehicle again. Something that was only equipped on heavy duty trucks with SBCs and all 454 engined trucks. The only other exciting things in the box were a Tekonsha trailer brake controller from 1990 and 5 flywheel bolts that can eventually be used for shoulder belt mounting.
The Suburban is still running great. I'm starting to run into people around town whom I've known for years, but they never knew that I owned a Suburban because it has been nearly a decade since it was last on the road.