1970 F250 360 not cranking over

[Oldpueblo250]

Hello, any suggegestions or help would be greatly appreciated. I’m having a heck of time getting my truck to crank over. Turn the key over and nothing? I’m able to start by jumping the solenoid with the battery and a screwdriver. I’ve replaced the starter solenoid, the starter, ignition switch, all fuses under the dash are good, battery is good. Should I replace the voltage regulator next? 1970 F250, 360, 2WD. Thank you.

[DuckRyder]

How are your grounds?

Everything follow the wiring diagrams @ http://www.fordification.com/tech/schematics_i.htm

[Mach428]

There is a plug on the passenger side behind the glovebox, up close to the windshield. Check to ensure the connection is tight. I've had this come loose and cause this very problem

[sargentrs]

These days just because you replaced something doesn't mean it's good. Solenoids are notorious for being bad right out of the box. First some basic troubleshooting is in order. Grab your voltmeter and check your connections with key off, key on and start. Hook your ground lead on the battery - side. Start at the battery + post and check voltage in all 3 positions watching for voltage drops. Then move to the battery cable end connected to the + post. Check in all 3 positions again. Then to the end connected at the solenoid. Then to the other side of the solenoid. Also check the small "S" terminal in all 3 positions. The wire on the "S" terminal us what triggers the solenoid to allow 12v to travel from the battery, through the solenoid, and down to the starter. If your getting power through the "S" terminal, it's not going to start. If all that checks out, check the connection at the starter. While checking the various connections you shouldn't see a voltage drop below 10v. If you do, start there. I've had a similar issue a couple of times. First it was the crimp on the brown wire from the alternator to the solenoid. Another time, the bell housing spacer was so grimy the starter wasn't grounding. Sometimes the simplest things can be so frustrating.