3 Starters in 10 Months???

It's possible the new starter works because the electrical contacts are very clean on the new starter and after riding around under the hood for some times enough dirt and corrosion accumulates that the intermittent problem with the ground wire shows up again. Or during the process of installing the new starter the fault with the ground wire is accidentally being improved (bumped or pushed aside). Once it's installed the bumps of the road have the fault working back into the position that creates the "starter" problem.

 

that's my very best thought

 

As @pushbroom said. Follow his recommendations.

More than likely high resistance in circuit. But you need to find it. New starter draws less amps than used. I can't guarantee anything. But battery cables from batteries to starter may need replaced. And any frame ground. Old dirty cables work like going for a jog with a straw to breath through.


Edit I mean @Goodysnap. Sorry Guys.

 

That picture is just a broken heat shield. No big deal. Do you have one of those Maxwell engine start module ultracapacitors? Starters will burn out prematurely due to low cranking speed. So like mentioned, the cables really need to be checked to make sure you are getting good grounds and positive continuity. You need to do voltage drop tests between the starter positive stud, and battery positive stud. Then the same between the starter ground stud and battery ground stud. 0.25 volt drop is ideal, but no more than 0.50 per side. Also test the batteries.

 

Do you have 3 batteries or 4?

 

I had the same issue. Went throug 3 starters within 5 months . Replaced the batteries and solenoid on firewall the last time I did the starter and haven’t had any issues since .

 

My personal vehicle did that..after the third starter in 7 years i wired push button switch to starter. I assume its my ignition switch but have not bothered to investigate further. No issues since.