Okay ..... my buddy has a 70 C20....... we have replaced the battery and the altenator...... he can drive it with no problems..... once he lets it sit for a bout a day or so without starting it the battery is dead...... now we cannot find any shorts...... does someone know what in the world could be going on? we can take the positve battery cable off while running and it doesnt die..... we put a voltmeter on it and it reads 15+ volts with the positive cable off....... once you put it back on it reads 12+ volts........ something doesnt seem right but i cant figure out what it is...... like i said both the battery and altenator are new within one week..... PLEASE HELP

 

what does the battery read with cables off?

 

it says like 12-13 but when it wouldnt start it was saying 8.5-9...... it is tempermental.... it will start fine one day.... run for 3 or 4 days and the next it wont start....

 

This may sound simple, but have the battery cables been changed recently? After 4 or 5 years they can corrode badly inside the insulation, and wreak havoc with startups and electrical systems in general.

 

sounds like a bad cell in the battery.....It doesn't happen too often with new batteries, but if they have been on the shelf a while without getting a charge into them it can happen

 

did you have the problem before you changed the battery and alternator ? because it kinda sound;s like a regulator that is shorted out ,or a fuse block that is shorted out .it's getting juice from somewhere !

 

Thanks for both of your replies.... okay i really dont think its the battery cause this is the 2nd new one in less than 2 weeks... thank god for lifetime warranties..... also the alt. is new .... less than 2 weeks also... it is a one wire system with the alt...... we have replaced the negative battery cable but not the positive... maybe will try that.... i have replaced all fuses in the fuse panel and nothing..... i put a volt meter to it on sun 9-7-08 and nothing showed voltage with the key off... i am at a stump on this but i know someone knows what is going on..... he wants to take it to a dealer but told him to wait cause thats going to cost an arm and leg and one of his unborn children.... someone help.....

 

Okay ..... my buddy called the guy he bought the truck from and he said there is a voltage regulator on it but i have searched and searched the underneath side of the hood and cannot what so ever find a voltage regulator..... Also.... his ignition you can pull the key out started... would that have anything to do with it?

 

shouldnt, as long as you have it turned off when you pull it out for the night, i have a '67 c-20 and my key comes out at anytime with none of the problems you are going through

 

alright...... well we have narrowed it down to some old wiring.... replaced it and wow..... PROBLEM SOLVED>>> god i hate wiring.....