Truck won't shut off

https://i.ebayimg.com/thumbs/images/g/oBEAAOSwunNd2hI4/s-l225.webp
This is what it looks like. It shuts down all "non-essential" electrical components when it senses that voltage drops below 12 volts. Problem is that when it malfunctions, the internal ignition relay sticks closed (on)

 

Did you check your ignition switch.

This is what my LVD module is.

 

Do what Quality suggests, he's a better mechanic than I,. Well I'm not a mechanic, just an OO that can turn a wrench.

Did you test the wires for power when you had them disconnected?
What Quality explained, I had no idea that was possible.

I would be looking for a power feedback from the starter ignition wire if your switch was good.

Good luck.

 

If radio and everything else shuts off with ignition switch, that should tell you the switch works

 

That's what I do. Change the low cost parts first, than ask for help here.
Owning a 99, time for most parts to be replaced, just for peace of mind.

Good luck with the repair. Keep us posted, I'm always curious about electrical problems. They seem to be the hardest to fix.

 

If that box qualitytruck mentioned isn't the problem, your shutoff solenoid is probably shorted to battery power.

 

Is that the solenoid mounted on the firewall by the treadle valve?