Follow the reset circuit. Find all the conditions that trigger the "reset" cycle and start troubleshooting those switches. There may be a leaf switch that is getting stuck or coil that is not releasing.

Do you use coins in the game? Check your coin switch. if it is triggered it will run the score motor continuously. Is your game set on free play or do you cycle the coin switch to add credits?

Do you have a PDF of the schematic? I looked on IPDB but it is not listed.

Ok, with the Schematic you can follow the line from the Score Motor to several switches that will complete the circuit to make the score motor run.
scoremotor copy (resized).jpg
I assume that the score motor is running when you say it is "resetting"

Not sure your level of expertise with circuits but I will be rather basic with this ...

Listed here are the direct switches making the score motor run. One of these is the culprit. However, these switches are controlled by other switches and relays as well.

Isolate the switch below that is making the score motor run extra and then you can narrow your search to just that circuit and associated relays.

- .10 & .25 relay switch
- IND "C" is Index cam on the score motor M/B switch. It keeps the score motor running through the cycle
- Target Count Relay switch
- Outhole Relay switch
- Reset Relay switch
- Coin Relay switch
- Shooter relay switch in green

Even though you have the jones connector disconnected from the door the Relays and more importantly the relay switches are still in the circuit and can make the score motor run.

You said you checked the switches on the score reels. Double check the "Zero Position" switch. If any one of these is making contact the score motor will continue to run. ***Check the screws that hold the switch stack are tight*** If loose they can be good candidates for intermittent problems.

Start with this and report your findings.

Easy fixes are the best!