My 6V battery on my 1951 Chevy Fleetline deluxe continues drain after every charge. The ignition switch, lights, radio, etc. are all in the off position. Where should I start the investigation to determine what is draining the battery?
Take off the positive cable and then put it back on looking and listening for a spark. If there is no spark have the battery tested.
First thing I would do is verify if this is a parasitic drain or will the battery just not hold a charge. Unhook the battery and see if there is a voltage drop over a period of time. Easy check to do but likely not the issue if the battery is not old.
Not sure how the 51 is wired but first thing I would do is take a multimeter and see if there is power to any fuses / items that should not have power when everything is off.
The following is assuming the battery is good. Grab a multi-meter. Disconnect a battery cable, I do the negative. Set the meter on DC Volts. Touch the red lead to the cable and the black lead to the battery. If it shows anything above 0 you have current flowing. Disconnect every electrical device, one at a time, until the current flow stops. When the flow stops you've found your problem child.
To Chipper, Mr87Monty and Tiny - thank you for your fast response and guidance! I will follow the advice!
If you do the spark test Chip mentioned, do it in an open space with air blowing on the battery. IF the battery is failing it'll be off gassing explosive gasses. A spark could cause an explosion of the battery. That's why I use the negative cable for testing.
Hi Douglas
You might also want to be sure the points on the cut-out in the voltage regulator are open and not stuck shut.
if the cut-out points on the regulator are stuck you should see a discharge at the ammeter.
If the car has the original wiring harness it would not surprise me if some of the insulation has broken off a wire. The result is a hard-to-find ground that drains the battery.
Thanks Sovblt and Rusty 37 Master! I executed the advice shared here. Didn’t find any “problem child” so I left the battery to sit without the negative cable attached. I have to leave town for the next 10 days so when I return, I will check the battery for loss of charge.
Put a full charge on the battery and take it to an auto parts store. They all have testers and will test your battery for free in most cases. You also have the option of buying an old analog style battery tester for around $30.