Positive Batt connector 89 240sx ka24e HELP?

[89singleslammer]

I bought a '89 240sx, man transmission, blowed motor, 200k miles for $200 and plan on putting my old ka24e from my other s13 in it (alradyown a s13 w/ sr). Just a buy, fix, sell for some quick cheese, guys over here pay $2300 for these cars runnin. The pos bat terminal on this car is broke.there is 4 wires. one is 2 gauge(starter right?) , one is like 10 or 8 gauge color is white (comes from alternator right?) and two 12 or14 gauge color is white (goes to headlights right?). Three of these wires plug into this plastic plug conn. thing. The plastic plug thingy is broke and is seperated from the bat. terminal. Well, I cut this plastic thing off and hooked those 3 wires to the pos terminal. When I did that my Emerg. Brake light on the dash is always lit up and i can use the headlights and the turn signals with the car off! This aint Right!! help?!!?Did I hook It up right? Can someone tell me the right way I was suposed to wire it up! oh, I got a chilton wiring diagram for this car and it didnt help at all, THANX!!

[89singleslammer]

does this help? Its off my car.