New battery keeps draining down to zero!

[DuncanR]

I just installed a new battery. However, if I don't drive everyday, my battery will be dead in about 5 days. Radio is off, lights, and all other obvious items. I've put my meter on the electric choke, ignition coil, and starter solenoid. My Bronco mechanical experience is limited, but I'm learning.

What are some items I should be checking to narrow down the culprit of the battery drain?

 

[ohpoo2]

Maybe try unplugging the alternator if its an old one could be a draw. had it happen to me.

 

[DuncanR]

Maybe try unplugging the alternator if its an old one could be a draw. had it happen to me.

Would you suspect this, even if the alternator was only a few years old? Also, can a Napa test the alternator to determine if it's the cause?

 

[Broncobowsher]

Remove the negative battery cable from the battery, wire a small test light in series. IF it comes on, you have a draw you can track. Unplug stuff (alternator, voltage regulator, ignition module, etc. until the light goes out. Plug everything else back in making sure the light stays off. At this point you have now figured which item(s) are causing the draw. The fix will depend on what the draw is.

Does the battery go dead even with nothing connected to it? That is a bad battery.

 

[2FAST]

Put your meter on the battery and start pulling fuses. Once you pull the fuse to the affected circuit your battery voltage will increase because the load is removed. Once you know the circuit start tracing components and wires. It could be anything. Best of luck with finding the culprit.

 

[GRN_MEANIE]

What they said about the test light. When I happened to me it was the voltage regulator for the alternator.

 

[Amac70]

many years ago voltage regulator for me also.

 

[DirtDonk]

Would you suspect this, even if the alternator was only a few years old?

Yes, of course. Nothing has a life expectancy these days. Nothing...

Also, can a Napa test the alternator to determine if it's the cause?

Probably not, but you can always ask. But it's easier to find out by testing it yourself as the others have suggested. If you find out that disconnecting the alternator eliminates the draw, that's your culprit.
Same for the regulator. It's just easier to disconnect the regulator than it is the alternator, but both can cause this.

If it's the alternator, it's not super bad. A really bad diode array will drain a battery in less than a night. Your five-day period indicates a fairly low draw, or a very weak battery.

Or both...

Paul

 

[Steve83]

I just installed a new battery.

What brand & size? From where? Read & decode the date code melted into the side of the lid to see how old it is. (Ignore any stickers.)

What are some items I should be checking to narrow down the culprit of the battery drain?

First, you have to determine if there IS an external battery drain. A bad battery can drain itself internally, so start by CHARGING the battery fully (that means with a CHARGER - not by driving it around), measure its voltage, then let it sit a few days & recheck.

Also, can a Napa test the alternator to determine if it's the cause?

YOU can test it. Click this & read the caption:



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