Ford used a few variations of starter systems. You have to list the engine size so I can look up parts which may be different.
Do you normally have to push the clutch pedal for the starter to work? That answer will tell me if there's a clutch safety switch in the circuit. Ford usually didn't use one, but we don't want to overlook that if there is one on your truck.
There's going to be two small terminals on top of the solenoid, and there's multiple versions of them that all look the same. It's common to get the wrong one. That will introduce a second problem. To be on the safe side, you may want to reinstall the original solenoid since the new one didn't help.
Rather than list all the different possibilities, start with the smaller red wire plugged in on top. Pull that one off, then use a test light to see if you have 12 volts on the wire when a helper turns the ignition switch to "crank".
Second, use a small jumper wire to momentarily connect that terminal on the solenoid to the battery positive post. Be sure the transmission is in neutral in case the starter cranks the engine. Does that cause the solenoid to click?
The answers to those three things should tell us where to go next.
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Tuesday, October 28th, 2014 AT 9:19 PM