Pontiac Repair: 1996 bonneville electrical problem, door locks, electrical problem

Question
I have a 96 bonneville SE 3800  and a couple of weeks ago I went out and started the car. it ran for a few minutes and then stalled. after the car stalled it would not start back up .after trying to start the car several times I noticed that the power windows,seats and door locks werent working . I then took the car to the garage and they said the reason it wouldnt start was a bad fuel pump. I then asked them about the other problems that they forgot about. so they looked further and said they found a bad connection at the battery and they fixed it. the car has been ok since until today. While driving the car it just shut off. I tried to restart it but it wouldnt start even though it turns over just fine after about 15 minutes the car started and ran fine for about 25 miles then it stalled again and now will not run at all and i noticed again that now the windows seats and door locks dont work and if I cycle the key a few times the car will start for a second and then stall as though it has low fuel pressure i'm pretty sure that it is an electrical problem but where do I look ?  any Ideas what would cause this.

Answer
Hey Kevin:

I know exactly what's wrong with this! Good catch on the seats and radio. The leads it right to the root of the problem. This car has a bad ground splice pack under the carpet on the left front of the car. remove the sill plate/carpet retainer and there is a large ground splice connector there. I'm sure it corroded! the fuel pump,seats,windows all share the same ground. Good luck :}