My car has had previous problems where it won't crank at all, there's power in the car, but it's not getting to the starter. About a month ago I used to be able to fool with the negative cable on the battery and it would sometimes cause it to crank, so I just tightened it down really hard and it hadn't given me a problem until this afternoon.

I'm really fed up with this, does anyone know if I could just wire up a switch to the pos and neg terminals on the solenoid and have it work like that? My boss' elcam is wired up like that.

 

If all you did was tighten the cable, you didn't solve the root problem - corroded terminals.

Take them apart, clean them up, replace if necessary. Don't go adding unnecessary wires and switches.

 

The terminals look fine.

 

Make sure there not stripped out. Im pretty sure you should have side post terminals and if thats the case the lead strips out easy.