Wouldn't the fact that all electronics work fine while the headlight don't dim and I tried jump starting while leaving it connected for a while to a running rig.
I'm not saying your idea is stupid just curious

 

The original repair to the battery cable could have resulted in a high resistance connection limiting battery amperage to the starter. Usually best to replace entire cable.

You can measure voltage drop across cable (positive probe at battery and negative probe at starter). Drop should be under 0.3 volts.

good luck

 

I figured that could be a problem do you think I should play it safe and replace the fuse box power cable and starter cable?

 

All electronics & headlights take a small amount of power compared to the starter motor.

Connecting jumper cables to a running rig kinda rules out a bad battery.

I'm a fan of measuring things not just throwing parts at it. But there's a price-point where it might make sense to replace stuff anyway. It might be a loose/corroded connection at the OTHER end of one or both battery cables. Or it might be a cable fraying & coming apart inside it's own insulation.

 

Please read post #3...

 

Yeah, in post #4 you say you hooked it up & tried. Somehow I missed that...

 

Got it figured out when I took out the starter and tested it. One of the three cables was corroded snipped it and reconnected Resolved problem
Thanks everyone