I had a similar issue with my score motor running because a coil in my score reel was dead so it could never return to 0 during the reset process. I used this link to help troubleshoot: https://pinside.com/pinball/forum/topic/williams-big-deal-help-please#post-2151431 You should be able to use that to figure out which switch is causing the motor to keep running. Then you'll have to troubleshoot the circuit associated with that switch because one of those switches will need cleaning/adjusting or maybe you have a bad coil like I did. I don't think you need to use electrical cleaner to clean contacts. Just use sandpaper or flexstone.