Is this wiring correct? Neo Cab to Wells Gardner k7000 monitor.

I was just looking at the wiring of the connector that connects from the Jamma harness to the monitor chassis board.

Whilst it works OK, it looks a bit odd. I believe it is a Wells Gardner k7000 model.

I was wondering if anyone could shed any light on if it is OK for it to be wired up this way or if there is a different/proper way to wire the connector up.

The pins on the monitor according to the manual from left to right are:

Red, Green, Blue, Ground, +V Sync, +H Sync, (then an empty slot), Ground, -V Sync, -HS ync.

With this in mind, why is there an orange wire connecting the +V and +H Sync together and why is the -V and -H Sync shorted together? Is this because JAMMA outputs only one wire for sync?

Also, the connector on the black ground wire that goes to the right side is broken so it doesn't actually touch anything? Does that not do anything either?

Your not actually using all of those wires. It uses R, G, B, video ground, and sync. Older games would use either positive or negative sync (not both) and both a vertical and horizontal sync wire or one wire jumpered between the two pins. Games now use composite sync, meaning both signals on one wire which is connected to +H sync. The monitor automatically splits and distributes the signal. If you follow some of those wires back they probably aren't connected anywhere. (try negative sync wires)

If you use an old monitor for a newer game but can't get it to sync, it might be jumpered. You can usually fix it by removing the jumper and using just +H sync.