Good morning all, I hope some one might be able to shed some light on this little issue I'm having, bought a 62 fleetside less than week ago , replaced batt , next day would not start {unless jumped} so i had alt chcked out , was ok, started noticing the chitty job that was done with most the wiring and the horn relay was prolly original, replaced it , it will start if jumped but not on its own , possibly could it be caused by to small a gauge wire previeously used or maybe the batt which is 650 cold cranking and 815 cranking amps too small a battery? I have experience with residential electrical but not automotive so any and all tips , hints , suggestions will be Greatly Appreiciated,,,,
Have you checked that you have a large (finger sized) ground wire from the battery to the motor? Same size positive to the starter?
Check your voltage regulator. I had a bad diode in mine and it would drain the battery after a few hours. If you have the mechanicle type check for proper adjustment. You can also try just unplugging the alternator when it is not running and plug it in when you need to run it. If the battery isn't dead then you know it's the regulator.