I've been at it for hours, so hoping I can't get steered in the right direction.

Bally Knockout. I don't have the schematic, but I found one for "Amigo" which looks about the same, particularly where I am looking.

I push the credit button, and the coin, credit and reset relays will all trigger. The reset relay will lock on, but score motor will not spin up. The score motor does work - I can get it to spin through a cycle if I activate the "HOLE" relay

I have gone through all the switches, all look to be in their proper state, and cleaned with a dremel wire brush. All the solder joints seem solid, and I can't find anything shorted. I have alligator-clip wires, but I'm not exactly sure how to go about using them to test.

Going through Clay's guide, it looks that the RESET relay should start the score motor.

So, what am I missing, or what should I try next?

-d

Yeah, that color schematic is nice.
I've looked at the Reset relay switch, and it seems right. I can squeeze an alligator clip into that one, and I get no change.
I'll look at the red-yel wires again

OK - I get like .3-.4 ohm between the red-yellow wire on the motor, and the white lugs on the relays. No change when I push the relay closed.

0.0 - 0.2 when touched together.

For what it's worth, I traced out that white wire. it daisy chains from the RESET to the 2nd COIN CHUTE to the COIN. From there, it doesn't actually connect to anything else. It does connect to the coin door jones plug, but that isn't actually connected to anything

Hmmm not exactly. The blue-orange and Black-white are one off on the jones plug on mine.

My credit button wires look to be pink-black and white-blue

For those who prefer a visual, here's a short video

I assume PBR has a schematic for this title. Can probably have it by Thursday.

That one is close - but I don't actually have a 3rd coin chute.

I guess my question is where does the white wire connect to the yellow rail?

Actually, the control board... ? Maybe I should have had a disclaimer "Don't try this at home" but my back thanks me

yes, which makes sense to me. I cannot find any way the white wire connects to the yellow rail at all.
I have thought about adding a switch, and connecting it to the 2nd coin relay, (there is no 3rd coin relay) as pictured in the Amigo and Wizard schematics, but I wonder if there is really something different in the Knockout schematics.

Negative. and yes there are previous hacks / mods, including credit wheel had been removed.
Then again, there's this:
The Coin Relay has 3 silver wires tied together on one side of the bottom switch. The other side of the switch doesn't seem to have any solder residue, or any other indication it was ever used.
CoinRelay (resized).jpg

Yes, we are on the same page.
Also I don't mind if this machine had previous kludges, but I worry most if there were an attempted kludge, that didnt work, before this game headed for retirement in a dusty, old basement.

I am reaching the opinion that the white wire needs to be connected to the yellow through a switch.

Will do.

With nothing to lose, I took that silver wire bundle off that lug, and cobbled together a hack, connecting the white wire on one side, and the yellow on the other. now, it sorta-kinda works a bit more. At least the motor starts, although it doesn't complete a reset sequence.

Anyway, I'm through tinkering with it until the schematic arrives.

Got the schematic - it doesn't look a whole lot different from the Amigo

IMG_20180207_173957202 (resized).jpg

Like the Wizard schematic, it shows the credit button connected to a white-orange and blue-orange pair.