car problem wont start help please

help me please!!!! i just purchased my modify '92 laser rs that my buddy built.the car was just at his house, so i decided to buy it. i purshed red top battery for it started up right away, only problem was the headlight would come on when we drove it they all of a sudden the lights stop working. almost a year later the car will not start. he said every week up he started it upand it ran. about a week ago i went get the car and it wont start . he said that he found the problem with the headlights and hooked up the wires. the car at first didnt trun over and did nothing. so i towed it to my dads house started messing with it. so this is were i am at.
1) the car tries to turn over took the starter out and got it tested and told its good but makes a loud grinding sound after reinstalling it.
2) if you take the two wires that run the headlights off the positive headlights dont come on, but the blinkers and interior lights do come on
3) but if you hook it it back up the headlights come on but no blinkers or interior lights don't. every time do this i try to start the car and still makes loud grinding sound. :banghead: :banghead: :eek7:

Your queston is really hard to understand. Are you saying that you think the car won't start because of the headlights? That does'nt sound right.
Is the starter lined up with the flywheel correctly? You might need to shim the starter. Also check your flywheel for missing teeth, or cracks.