No spark at coil during start

[OrangPeEL]

GT piggyback rode a wrecker home last week. It gave me a couple false starts and then just empty cranks. No spark at coil. It had not done this before. While typing this post, I believe I may have thought out my "stumped situation" into specific questions/solution; so, questions first and then the "set up":

• Is the coil resistor wire always powered with ignition on; supplemented with 12v switched by internal contact in the solenoid during start?
  
• Possibly I had no supplemental start voltage at coil (maybe due to failed contact in solenoid...revived by bumping) and cranking starter robbed juice from already resisted coil supply for spark?
  
• I could have push started the car and driven it home...and dipped into "The Opel Fund" for new wire, starter repair, and/or relay for an alternate 12v coil start supply....instead of the towing?

Set-up:
It is stock start/run set-up... except: push-button/relay activated start solenoid (applied to/in-place-of black/red at column loom). I recently removed an extra coil resistor ballast (by PO) and have enjoyed misfire-free loaded running! I figured the original appearing 35 year old coil must have cooked...(did I just say figured? I meant ASSuMEd)...so here I go!

I had new parts at home and began throwing them at it first... and THEN tested the old ones to be "OK" after there was no change. Coil, condenser, verified points ground function & 12v (unloaded) at the coil. I did NOT test solenoid lead independently for 12v out.

I noticed with spark tester on coil, I was getting a brief spark flash at depress and release of the button... with coil voltage [dropping] and no spark while cranking. Sooo, I bumped the starter about a half-dozen times this way and cranking spark returned! Great... but I'm not sure what failed and then corrected. I'm strongly considering driving to the Tacoma meet & need to get a handle on this... so Advance Thanks for input!

[OrangPeEL]

...so I'm going with this (from above post).

Thinking about adding a diode to coil 12v lead, and then just tagteam off the starter activation spade with existing start circuit wires. I don't run start current through the ignition switch anymore (pushbutton & relay).
Is stock gauge solenoid activation wire adequate to also supply coil draw during start?

Advance Thanks!
-Dan

[OrangPeEL]

Using existing wiring, I have bypassed suspect (intermittent defective/failing) 12v ign. coil contact in starter by tapping-in on activation terminal through installed (6A) "NTE 5815" rectifier/diode.

Appears to be working as intended. This may also eliminate my occasionally experienced need for excessive cranking I've thought caused by vapor lock, cold blooded-ness, flooding and/or evil demons.

[wrench459]

Originally Posted by OrangPeEL Is the coil resistor wire always powered with ignition on; supplemented with 12v switched by internal contact in the solenoid during start? "I dont thing so its handled from the ignition switch run contact. not the start contact thats your bypass circuit in the starter solenoid" Hummm most ignition switches bridge the start and run contacts.. sounds like the low current probe is coming home one night to find out. I could have push started the car and driven it home....instead of the towing? "Possibly"

Isn't it fun working on cars.