Nissan Repair: Eletrical problem, gauge wire, fuse box

Question
I just bought a 1997 nissan 200sx 1.6l 4 cyl
I was noticing how the car turned over slow so I thought maybe a battery going bad. I looked at the battery connectors and they were really coroded..especially the positive cable. I went to the autostore and decided to replace both the negative and positive cable. The negative has two points..one bolted to the frame and the other to the tranny (the autostore ones only allow you to connect to one end so I picked the tranny). The positive is a straight fwd wire to the starter..only thing is that there is a secend small gauge wire that goes to a fuse box which is attached to the battery tray. I spliced a connector to the positive terminal.
  The problem still persisted but now the headlights and the whole power system of the car is dim..and then suddenly engine goes dead. I was not able to start it and there is not enough power to start the car. I tried another good battery and it started for a little while until I turned on the headlights and then the car went dead and I was unable to start it again. I used a battery cable to ground it from the negative terminal to the block or exhaust manifold or vice versa...tried to attached the cable from the exhaust manifold to the frame thinking it might be a grounding problem? I am stuck and the car will not start...all your help would be greatly appreciated.

Answer
Ken,

I always go with the factory cables.  But, since you have aftermarket I would connect one from the negative to the frame and you should be good.  But, after you get that extra ground attached I would then charge the battery and then go down to Autozone or the like and get the charging system and battery tested to make sure you have good output and storage too.  But, it is vital that you add that extra ground wire from the battery to the frame.