1998 mustang wont start has no crank or noise when you try to start it replaced ignition switch but still nothing what might be wrong?

Answer 1

You should hear a click sound from the starter solenoid, that is a relay that switches the high current connection from the battery to the starter when you turn the ignition switch. That would click unless battery is dead or has really bad connection and isn't getting voltage. Most often problem with starter motor turning is bad cable connection at the battery, especially if there is recent damp weather, usually owners who don't know importance of good connection. I remove the battery cables whenever slight problem turning, and clean the battery post with sandpaper and on clean on inside of cable connector. Make all areas shinny, and don't think it doesn't matter to do carefully as it does have affect. If working on motor recently, it must have ground cable to car frame for starter to work. The old system to test if starter is to short with screwdriver from hot battery cable that attaches to starter connection, short that to the lead that goes into the starter motor but use care not to ground any part of that procedure (always took a little nerve in old days too), maybe better info on that on internet. Some Fords have starter solenoid separate and mounted on fender well or like place, which might be easier to work on, keep searching forums for advice (how rest of us fix cars now).