Ford had at least three different solenoid / starter circuit configurations. To save time, start with the battery disconnected, then use an ohm meter to measure between the two fat terminals on the solenoid. If you find 0 ohms, or very low resistance, bang on it to see if it goes to an open circuit, (very high resistance). If it does, the contacts are worn and the movable disc is getting wedged between them.
There's three different versions of solenoid Ford used. Your best bet is to look for a part number for the people at the auto parts store to cross. They all use the same small terminal that's hooked to the ignition switch, but one version has a second small terminal that has to go to ground through the neutral safety switch. On other versions that second terminal is for bypassing the ignition resistor for easier starting. If you ground that one, you'll have a burned-up wire.
Monday, May 4th, 2015 AT 8:12 PM