Aftermarket fuel shutoff solenoid.
 

Has anyone used an aftermarket fuel shut off solenoid from RockAuto, or O'Reilly's Etc? My truck is starting to act up on starting, I'm having to manually flip the solenoid up to start the truck

We have them.
https://www.dieselperformance.com/sh...alve-p7100-820

I have purchased one from Rock Auto. It was significantly cheaper, but I did have to do a little monkeying around to have it work. It has been working fine, only one issue since install. The solenoid mounting bolts loosened off and had to find the correct bolt torque so the plunger does not bind in the solenoid. Just check the solenoid relay before changing the solenoid. A cheaper fix if it is the relay. I had to change mine after putting in the solenoid.
chucks

I replaced mine with multiple OEM and aftermarket ones, including the relay, and eventually got so fed up with the whole arrangement that I replaced it all with a vernier locking cable. Problem solved. Also: most people don't know how to start it now.

little blue wire, driver side battery. make sure that connection isn't corroded.

I did the same..took a little tinkering to set up, but works flawless...and like you said, if you leave the handle out..it's a no start!