Ok - im fixing my WMS 64 PALOOKA which has been kinda screwing with my head. I had a few faults with this including a very strange mod on the score motor which is bloody odd!!
The game is a 5 ball add a Ball game same as Gulf Stream - i got the start up to a point where once coin door button was pushed, game would TRY to start but not credit balls and not put ball into play. The bonus unit in the back would DECREMENT 5 steps instead of INCREMENT... first reaction is to assume that wires had been installed incorrectly during someones fix up and swapping them over would reverse the symptoms - seems reasonable.
Not so - solder is original

Fault was in the GAME RELAY - there is a 2 way leaf switch, when it pulls one way, it DECREMENTS, it then reverses and INCREMENTS - this is the normal start up sequence.. it HAS to go one way and then the other.

I looked at the Gulf Stream schematics to see if the circuit was the same and it is... the INCREMENT and DECREMENT circuits are identical although judging by your pictures, it is installed differently ( increment is under the PF and i believe is 3 in line relay - something like that anyway)

BUT...... The relay to check is the 2nd to last at the back of the cabinet - its on a metal plate and is GAME RELAY - 2 way leaf switch is on far right.
Adjust this so there is only a tiny gap when it is open... it needs good tension to operate properly

LOOKS LIKE THIS



Let me know how you go and ill go have a look in the back box for you