On my 68' bronco, I have a slow electrical leak somewhere. If it sits for more than 2-3 days, the battery is low enough, it will not start. I checked the accesories, and can't find it there. Is it possible the alternator or the voltage regulator could be the culprit? Thanks!

 

It could be the alternator. The best way to find out is get a testlight and set it up like the diagram below. Then if you pull the alternator wires off, and the light goes out, then you know for sure it's the alternator. If it's not the alternator, then you can pull fuses till the light goes out.