Intermittent crank no start

Done what, check the connector? You need to check for voltage drop all along the path. The closest point you can easily pick up the supply point for the key is where the big red wire from the fuse link enters the bulkhead connector, at the firewall. Check this UNDER LOAD in other words with key in "run." Note that voltage

Next would be other side of the that connector in other words up under the brake pedal, but that is difficult. From there the ammeter, but that is difficult

So now, access the ignition switch connector where it leaves the column. You have the wire going "in" is the hot 12V into the key from the ammeter splice, a continuation of where I just started. You have a connection there, so check both sides of the connector, for voltage, and wiggle it, maybe even work it in/' out

Then check the output going OUT of the switch the "ignition run." If that is noticeabley lower voltage than where you measured out at the big red on the firewall, you have found some drop.

Next, measure that same line---the IGN1 "run" wire--out at the firewall connector in the engine bay. If it has dropped any from the ignition switch connector reading, then you have a poor connection in the firewall connector for that wire

So the functional path is sort of this:

BATTERY, FUSE LINK, BIG RED TO FIREWALL CONNECTOR---through connector to AMMETER on RED, through ammeter and out BIG BLACK to WELDED SPLICE, branch off and feed to IGNITION SWITCH connector--through the connector and TO AND THROUGH THE IGNITION SWITCH.....out the switch on the IGN1 "run" wire----THROUGH THE IGNITION SWITCH CONNECTOR--to and THROUGH THE FIREwALL CONNECTOR, and BRANCH OFF and feed the ignition system, alternator field , VR, electric choke if used, etc etc.

Now your coil+ readings aren't that bad, but some low, and the CRANK voltage is rather low.

So now you need to check the path for drop for the CRANKING circuit, here is how that works. The ignition system has TWO power sources. The IGN1 "run" wire IS ONLY ENERGIZED with the key in "run." That goes DEAD when you twist the key to "start."

HOW DOES the ignition circuit get power in "start?"

You have a SEPARATE switch contact/ circuit, marked IGN2 which is ONLY energized during cranking. This is DIFFERENT and SEPARATE from the "start" circuit to the start relay, but works the same--it is "hot" in "start."

This contact only goes one place---via (usually a brown) wire out through the firewall to the coil + side of the ballast.

THIS IS WHY it is important to do testing by twisting the key rather than jumpering the start relay, because you have different situations.

So same deal---check for voltage drop, and take your readings WHILE cranking the engine WHILE twisting key to start.

This is COIL +-----to firewall connector BROWN (look that up or post back)---through connector, IGN2 wire goes from firewall connector to IGNITION SWITCH CONNECTOR where you can measure that as before-----through switch and out switch and to SWITCH CONNECTOR to the BLACK supply which is hot.

EACH OF those switch contacts and wire terminal/ connector points is a place for corrosion, damage, and voltage drop

AND THE SWITCH ITSELF

To fix voltage drop in IGN1 you can install a relay in the "run" wire where it leaves the firewall, and if necessary, you can also "fix" the IGN2 bypass circuit also with a relay.