The first step in installing the completed cable was to attach the quick disconnects to the microswitches on the coin door. There are two microswitches, one for each coin mech, and they're mounted on the left-hand side of each mech.
There are three tabs on each switch, but you only need two. The tabs are labeled, usually with a "Com" for Common or ground, an "NC" for Normally Closed, and a "NO" for Normally Open. Sometimes there's a graphic instead, but it should be fairly clear which tab is the common one, and which ones are the normally open and normally closed tabs.
The ground wire should be attached to the common tab, and the coin input wire should be attached to the NO or Normally Open tab.
Once the door was wired, it was time to connect the other ends to the keyboard encoder. My SlikStik control panel already had two buttons wired up for coin inputs, and I decided, in a moment of weakness, to leave the existing coin buttons wired up in addition to the coin door inputs. (Someday I'll remap the coin buttons to some other function, but for right now my kids are big into games with "insert coin to continue" features, and they're just too small to keep hopping off their stools to insert a coin each time they die.)
The inputs on the IPAC are labeled, so just look for the Coin 1 and Coin 2 spots on the terminal strip. Using a small screwdriver, loosen the screws for those inputs and insert the wires, then tighten the screws to hold the wires in place. Be sure and do the same for the ground wire.
Once this is finished, everything is wired up and ready for action! Fire up MAME, start a game, and pop in a token. Ah, just like being in the arcades...
Switching over to token operation is probably not for everyone: there is a bit of work involved, plus it costs money for the new mechs and for the tokens themselves. Still, I've got to admit I'm really happy I did it: there's something about putting a coin into a machine that just brings a wave of nostalgia washing over me each time I do it.
If you're looking to add another layer of "arcade authenticity" to your gameroom, I definitely recommend the token switchover. I've even started collecting tokens from arcades I visit, building a unique "museum" of sorts to preserve yet one more aspect of the arcade experience.