J1

P1 - White (GI Return)
P2 - Green (GI Return)
P3 - Not typically used (Switched Illumination Buss spare)
P4 - Key
P5 - Orange (GI Buss)
P6 - Brown (Solenoid Buss)
P7 - Blue (Switched Illumination Buss)
P8 - Red (GI Buss)

There are the ~typical~ wire colors. You game may not be using the white and red GI wires (or they got hacked in somewhere else, look around) and i'd bet that gray wire is the solenoid bus. Maybe follow it to PF or DMM check it.

Looks like you need to re-crimp that green wire and maybe some others. The insulation jacket should just be on the out most crimp part. Bare wire in the middle inner crimp part.

The gi is split into two runs to reduce current draw. keep it that way.

if you have all the current going through one connector contact because wires are hacked together it will probably burn up again unless you use LEDs.

Either led or incandescent your best off to repin the connector the same way it originally was done.

Look at the PF near the back and find where the GI runs start. Do you have four differ wire colors for GI? If so follow them back through the harness and recrimp wires to where they originally go.

Hah thats a good one using the the metal shielding as return. Pretty much laziness and/or lack of tools/equipment to do it right. Not the end of the world but I would not leave it like that. Can't remove the playfield without taking that off.

Proper fix would be to split those wires up and crimp individually. Put them into the connector position where they should go. Looks like J1 P1 and P2

Some games had two wires so two holes where included on the PCB. If you have one E10 wire it doesnt matter which hole you use.