Starter solenoid circuit 69 FB
 

Still trying to chase down a problem in the starter circuit on a 69 FB. I just need a sanity check here. Which wires are needed to initiate the solenoid and begin cranking. I believe that the red wire attached to the ignition switch passes current to the purple wire then through the clutch safety switch and then to the starter. Are there any other wires involved when you turn the key to initiate cranking?

No other wires, other than the positive battery cable at the starter solenoid. The starter also has to have a good ground path back to the battery.

What's going on?

The "S" terminal on the solenoid will be a big gauge purple wire that has 12v on it in the crank position in park or neutral or it the clutch is depressed on a manual trans car. The other "R" terminal is where the wire goes that supplies voltage to the ignition coil. :)

I looking at my original post I guess I should have been clearer. I have a bad connection/broken wire somewhere underdash. If I unbolt and lower the steering column I can get the car to crank.Move it back to proper position and it's dead. I have replaced the ignition switch but my question was really concerning the interior wiring I can't seem to locate any obvious breaks or bad connections. I wanted to make sure that no other wires were involved before I begin unwrapping wiring harnesses

Automatic or stick?
 

Starting dropping column sounds like an automatic car with neutral safety switch or trans lock out linkage out of adjustment.

No need to un-tape. Probe the purple wire at each terminal end till you find where the power is being lost. Start at ignition switch and work your way down. You've got ignition switch, clutch/neutral safety switch, firewall/bulkhead connection, and then the starter. Purple wire shouldn't have any breaks in it other than listed switches and connections.

Worse case scenario would be a poor connection in the bulkhead/firewall connection.

Also a poor connection on the battery/power wire to ignition switch could cause it. And moving the column is just putting pressure on a lose terminal.

AND

A poor connection can still have 12 volts, but not have good enough current/amp flow. It takes quite a bit to energize a GM solenoid.

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