Hey guys, new to this forum. I've got a 1993 F150 with a 4.9L. I'll give a rundown about all the things wrong. Start on the ignition stopped working so I hooked up a momentary switch directly to the relay (solenoid on the wall) and that seemed to work just fine. Battery would only get maybe three attempts to start if you didn't get it started right away so there was either a drain or it was going bad. I broke down and it was acting like the battery was dead so I replaced it and no go so I figured the starter was toast. Bump started it and got it home, replaced the starter and solenoid and now it will start but the starter keeps spinning, so I swapped it on warranty thinking it was a bad reman. Still spins. Thinking maybe the old switch was the problem I ran the signal from the solenoid and the relay to the cab with another to the relay to "hotwire" it, starts and still spins even after all wires are separate. Now thinking a bad ignition switch maybe is still sending a signal somewhere I replaced if and it's still doing the same thing. Any ideas because I'm out of them?

Also, what are the other wires on the relay?

Thanks in advance,
'Red

 

Do a search on your wiring schematic. See if you cant download one or refer to it in a maintenance manual, if you have one.
Grab your multimeter and chase down your wires. See where the voltage is coming from. Shouldnt take too long as the starter systems are pretty simple.
The starter will only crank when the circuit is energized by the solenoid.
Also be sure to inspect and clean all ground contacts...the wire lugs, and mating surfaces. They need to shiny clean.
You turn the key tumbler, which moves the pushrod to the ignition switch, which then sends 12v to solenoid, which closes the starter circuit via the solenoid...and cranks the flywheel.
It sounds like a loose key tumbler, bad ignition switch, or chaffed wires under your dash by the steering column....perhaps from an aftermarket item install.
Spend some time chasing voltage and save your money before buying more parts that you may not need to fix the issue.

 

In your testing, have you bypassed the relay and jumped straight to the starter to see if it will turn and stop turning when you disconnect from the battery? I've had the points stick on a relay and the starter continue to run.