I recently acquired a Gottlieb "Top Card" that someone had modded. I don't know anything about the history of the machine. It had all sorts of problems to begin with, so I went through all the switches, removing each stack, cleaning/gapping, etc. After getting the steppers moving smoothly, it all pretty much worked.

But it had some extra parts: Someone had put an extra relay down on the bottom board (looks like a Williams relay), put an extra n/o switch on the outhole, and connected some of the wires with a nice little 2-connector Jones plug. It was all nicely done, but I can't figure out what he was trying to achieve.

Here's a pic of the extra relay in there. The wires with the connectors on the ends go to the n/o switch on the relay - they're just hanging out there - weren't connected to anything when I got the machine, so I don't know where he had them hooked in.
e extra relay (resized).jpg

Here's more lamp cord - showing a connection across the n/o side of a m/b switch on the S relay, then through the Jones plug. The other side is going up the underside of the pf to the extra outhole switch that he put in.
e more lamp cord (resized).jpg

The underside of the pf with the nice brown lamp cord:
e lamp cord to outhole switch (resized).jpg

The extra outhole switch:
e extra outhole switch (resized).jpg

So I traced the wires and it looks like this is what he did (except for the 2 unconnected wires which were across the n/o switch on the extra relay) - the added stuff is in red:
Top Card mods (resized).JPG

So, does anyone have any ideas what he was trying to achieve with this. He knew enough to install a new relay, Jones plug, switch, staple the lamp cord pretty neatly to the underside of the pf, and his soldering wasn't terrible.

By the way, I tore it all out (well, unsoldered it), and the machine works perfectly. I'm just curious what he was trying to achieve. Maybe it's unanswerable with those 2 leads from the relay switch not connected to anything, but if anyone has an idea, let me know.