I did the 12 volt change on my 54 gmc runs and stars but the battery is real low in the morning i tested to see if it is charging when running that is good how can i find what might be draining it
Battery Drain First , charge it well and leave parked overnight with the ground cable un done and tucked down behind the battery ~ In the morning go see if it cranks fast & starts easily before sunup . if so , the battery is fine , you need to use a test lamp between the ground cable and battery post to see if it glows a little bit , indicating a current leak . If it cranks slowly , the battery is kaput even if it's brandy new . Report back here and we'll walk you through it , it's usually *very* simple and easy to fix .
When running, the Alternator/Generator should be charging at 13.7 to 14.3 volts. If this is within range, try disconnecting the battery overnight and check battery voltage first thing before hooking up battery in the morning. If the battery has 12 volts disconnected, hook up the ground (Negative) side of battery. Use a multi-meter, set on DC Amps, and hook it between pos. cable and pos. terminal on battery. See if there is current flow, with everything off. ( if you use a test light here, it will glow in varying intensity, depending on the amount of current draw. In any case, it will not burn brighter than full intensity). If you indicate current draw, try disconnecting things you might suspect, one at a time, until the current drops to "0". Try disconnecting the Alternator first, as they have a number of diodes in them and are subject to 'leaking' current. Hope this helps. Others here may chime in with more or better advice
Current Draw If you used an alternator or installed any sound system , disconnect their wires and tape carefully then re test for the current draw ~ often the test lamp barely lights up . 99 % of the time , the exciter wire for the alternator is the culprit . Amps too , draw current when not in use . This is why the smart Hot Rodder uses those cute little cube relays to power everything so when the key is off , no current goes anywhere .
exciter wire the alternater exciter wire MUST have a one way diode or it will discharge the battery with the switch in the off position.
Nailed It Yes and no ~ first : disconnect the exciter wire and see if the battery remains charged over night . If so , contact Randy Rundle @ 5th Avenue Auto Parts and tell him Nate says you need the diode thing , he'll need to know *exactly* which alternator you're using and will send you a thing to fix this . If that's not it , congratulations ! you've eliminated one thing . See ? I tolja it'd be easy .
Ok so with exciter wire disconnected reconnected and it started. So now i ran for a bit im going to leave the exciter wire connected and see what happens if it does not start ill order the diode thingy
