I have a 3.0L V6 2000 Ranger XLT Extended Cab. It's done me good. One day, my starter died in my work parking lot. We have free parking, so I got it fixed when I could. Ran and started up fine for about 8 days until I tried starting it up at my house to go to work. The starter would not stop turning the engine over. It kept going until it was burnt out. From that, I've put in two new starters w/ solenoids, replaced the ignition switch, rewired the starter and solenoid a dozen times, and replaced a blown 50A starter and ignition switch fuse/relay. I can't think of anything else that could be a problem. What can I do, other than get a new vehicle, which is not an option for at least 2-3 months?

 

Welcome to the forum

2000 3.0l Ranger will have PATS(passive anti-theft system)

In the engine fuse box is the PATS Starter Relay

When you turn on the key, the key is tested for an ID number, if that ID number is in the computers memory(programmed) then Computer will Ground that Starter relay, so starter can be used.
This doesn't activate the starter, it allows the key to activate the starter when it is turned to start.
It just Grounds the relay's coil

Here is the wiring diagram for 2000 3.0l

If you look at the pathway from key to starter relay you will see the Neutral safety switches depending on transmission type
Both of these switches have 12volts present on other wires when key is on.
So you could have a short in one of these that is sending 12volts on starter relay wire so starter continues to run.
If you pull out the starter relay you will see the slots one slot will have 12volts all the time, you want to find the slot that only has 12volts when key is turned to START
Hook up test light or meter to that slot and then start moving wires around at the neutral switches