Electrical problem
1996 Ford F150 6 cyl Two Wheel Drive Automatic 172000 miles

I had a few starers put in but it will run ok for a while and now, again, it will not start. I had it tested and the battery is ok . It is getting a weak signal to the solonoid but my BRAND new terminals were very corroded. I cleaned them and tried but nothing. I then tried to jump it and got some clicking. I tried again and when we hooked up the cables to the other car it threw offf big time electrical sparks. Any ADVICE?

replace the starter solenoid and also get a new battery or have the old one tested and charged up.