Won’t start

[Van.truck_guy]

So I have a 1988 Ford ranger stx 4x4 with the 2.9 in it, I got it and it didn’t run because the guy who had it before me fried the harness but I got all that sorted out and replaced the starter solenoid and battery, after that it ran and drove but since then it’s had an issue with the starter solenoid goin bad, I’ve had it for 3 years roughly and it’s been replaced 3 times, any idea why it keeps goin out?

 

[Nelson and Hudson]

Have you bench tested the alternator?

 

[Eddo Rogue]

Id start with checkin stuff