How do I repair this; can I strip the wire back further and if it looks better , cut and reconnect the terminal or whole new line don't bother cutting back? And can this cause a slow crank (barely turns over and catches ignition to start) and at times no crank? (just the dreaded clicking of the solenoid) or if there i another way to eliminate the corrosion I AM ALL EARS i MEAN 4 EYES🤓

I hope you can see corrosion inside the wire the pics don''t do the easily spotted (once I took positive post red cover off.

Different angle

 

i went ahead and stripped back the insulation and cut about an 1-1/2" off both the smaller +/- 6 gauge and the larger that I believe goes to a junction where it connects to the alternator then continues to the starter solenoid. Unfortunately, for me, I have to pull the starter and do it carefully; 2 brake lines and an engine monitoring sensor that looks very fragile below it too, gotto love engineers. They should be forced to help pay for recalls or something to wake them up. so, tomorrow looks like pull starter and check connections, battery disconnected for the night at 12.78vdc if it's the battery i should know in the morning if the voltage has substantially changed. Please let me know if i am hunting with the wrong dog...

 

starter solenoid clicking...yes, a bad connection can cause this. you can test the Insulated and grd circuits in one short swoop via voltage drop test but the vehicle has to crank over. A bad battery can also cause the solenoid click. if the problem remains, have a shop load test the battery.

 

Turned out to be the battery, my charger is real, actually sometimes too picky about what it claims is a good battery and what isn't. It would however, on the low 2A setting, easily charger and go into standby mode the battery in question and that was what initially had me looking elsewhere for the problem as I had already tested the alternator. I disconnected the battery and by the next morning it had dropped in voltage to under 10VDC having been disconnected with a charge of 12.5VDC. Thank you for your time and thoughtful comment!