Lincoln/Mercury Repair: 95 F-150 starter problem, selonoid, starter problem

Question
When the key turns...no start! just clicks. When jumping the selonoid it starts right up. I have replaced the selonoid, the wires from the selonoid to the starter, the ignition switch and key switch and have had the tested and it's good. I'm at a loss and scratching my bald head. Can you shed some light? Thanx in advance.   Doug

Answer
Well Doug, I would have said solenoid, but since you have replaced it, next I would look at the charging system. Since we know the starter works let's check the alternator output with the lights on, a/c on, everything on and check with a VOM with the meter on the positive side. Disconnect the cable after it's started and touch the positive side of the VOM to the positive cable and the negative side of the VOM to the positive battery post. With everything on it should be over 12 volts. If it is, then I think your battery may be weak.