Ok guys i have a 1990 5.0 GT. My problem is when i crank the motor over, the starter won't disengage, it just keeps cranking the motor over. If i turn off the key, the motor will continue to crank until it has no battery power. While it is cranking over unwantedly if i hit the starter solenoid it will stop cranking over. I have replaced the starter, the solenoid, and the battery. I'm thinking it is a wiring issue, but where at? Any help will greatly help.

 

If you have to hit the solonoid, it'll be the solonoid. What you can do to check it though, is, get a test light or volt meter, semi-disconnect the ingnition wire to the solonoid and touch the end of the volt meter to that or test light, and the other to a ground. Then that'll tell you if it's wiring or solonoid. If it constantly gets power from the ignition, then it's wiring, or ignition.