I am having some problem with a 97 Nissan Sentra starting and charging system. It first would not start but would get lights on the dash, so I had the battery and alternator tested both on and off the car. They both tested bad (12.9 volts output on the alt), so I replaced the battery and got an alternator. It started with the new battery, but I could tell it was getting weaker with each start, this is when I had the alt tested. When I was replacing the alternator, I had the negative battery cable still attached, even though I know better (wasn't thinking, I guess). Anyhow, I got a little spark off the alternator when replacing the radiator which contacted one of the electrical connections on the alternator, (I had to remove the radiator to have enough room to work). When I got it all back together, it would not start. It had instrument panel lights, but would not turn over, it was drawing power, though, as I tried to jump it off my truck and it weakened my charging system when I'd try to start it. I went and had a full charge put back on the battery. I replaced it and tried ot start it again. When I did this, the instrument panel lights were on, but after I tried to turn it over, turned it off and then tried to turn it again, I got nothing, no lights on the dash, no sounds, etc. I wonder if I damaged the alternator when it sparked (but even if I had, how would this keep it from starting? I am under the impression that the charging system has nothing to do with starting, but only keeping it going once started, but could I have caused a short in the alternator that is keeping a circuit from being completed?). I thought it might be a fuse or something blown, so I looked at everything I could find that might have something to do with starting and charging. They all looked fine, except I do not know how to visually inspect the fusible links (or what I think are fusible links or maybe relays, block-like fuses in the fuse box under the hood). How are these visually inspected? Do you have to have a meter to test them? Could I have damaged the starter doing this? It seems like the absence of lights would indicate a fuse blown, but I cannot find one that looks bad (of the 'mini-fuses' anyhow). Are there any inline fusible links or relays I should look for? I may have to remove the alternator again and take it to be tested. Does anyone have any ideas on what I should check on next to get dash lights, and get it to turn over? I know that there is nothing wrong with the battery/cables, and the starter did work fine previously.

Thanks for any help,
Paula