Hey I just bought a 69 Ford ranger, it has been running since I bought it and have drove it around, but yesterday I went out to crank it and it wont crank. It makes a clicking noise when I turn key to start it. I had to end up jumping it to get it going and it ran fine but the same thing happened again today when I tried to start it. Any help would be appreciated greatly

 

Possiblities...

1. Battery going bad.
2. Alternator/voltage reulator failing or failed.
3. Parasitic amp draw when the ignition is in the OFF position.