Here's the story: this guy built up a 93 cavalier (2.2L motor) for 1/3rd mile oval racing, with a full cage, fuel cell, and a slightly built up motor and modified tranny, he's got well over $5k invested in it. Then, 6 races into the season, he completely destroys the car. So, he gets an 89, cuts the roof off both cars, moves the cage over, and then swaps over the motor and tranny, along with the fuel cell, but never finishes the wiring. He did, however, cut a bunch of wires he deemed unnecessary. Fast forward, he gets busy with a new job, no longer has time, and my buddy sees it, says "Hey, I know a guy who can do wiring" (yeah, that's me), and buys the car for $500. What he failed to realize is that I usually work on imports (Hondas, old Toyotas, Nissans, etc), have never completely redone an engine wiring harness (especially not when half the harness is cut or missing), and I need at least a manual (which he won't buy) to go on. Here's what I'm hoping you guys can help me with:

Running the motor: is it just the ECU and "gauges" lines that need to be hooked up? The ignition switch has a key broken in it, so we're putting in switches, and want to reduce the wiring mess to just a couple inline fuses. Fuel pump already has its own switch.
The brown plastic box under the dash on the driver's side with the door buzzer in it: any engine related functions to that? There's only 2 wires still connected to it, can't remember what color they are atm.
Which side of the motor, looking at it from the front of the car, should the fuel pump and return (fuel) lines connect to?
Are there any scans of service manuals or wiring diagrams kicking around for this? He refuses to spend $36 for a Haynes, I should tell him I need the $105 Helms.

Thanks for any help you can provide.

I have a 94 factory manual, but the ECM wiring is different, since they just switched over to the 1/2 OBD I, 1/2 OBD II deal. The brown thing under the dash has nothing to do with engine function, its the "convenience module". It controls interior lights, flashers, etc. Nothing engine wise. The engine harness is seperate from the interior harness and goes through the pass side cowl. The ECM does need to get ignition hot, etc in the 3rd connector, but again, I don't know the 93 wiring pinouts. Haynes won't have any of this, you need the Helm. Try ebay, then just charge him the extra $50. I see them on there sometimes. Or go on V6Z24.com and check out the maintanence forum. I'm sure someone there has a 93 manual.

The fuel lines don't attach at one end. Looking at it from the front, the supply is on the left, and the return is on the right, but it actually attaches to the FPR, which attaches to the manifold.