Battery keeps draining.

2002 4 runner 4wd.
Runs great for a couple of days and then dead bat. Jump it and it runs great for a couple of days and then dead. Any thoughts? Nothing is on.

 

"Nothing on." Take it to Auto Zone or any auto parts place and have them check your alternator output. If it tests okay? It's bleeding off somewhere?

 

Voltage across battery terminals while car is off?
If you have under 12v while car is off, and the battery has been charged, the battery needs to be load tested or replaced.

Voltage across battery terminals while car is on?
If you have under 13.4v while car is running, alternator needs to be load tested/replaced.

Have you removed battery cables and cleaned all corrosion?
Have you inspected battery cables for damage/internal corrosion?
Bad cables cause these symptoms.

If all the above tests out OK, test the current draw while car is OFF by using your multimeter inline with a battery cable. More than 50mA is a parasitic drain. I think normal may be more like 20mA for these cars. If it is like 50mA or more, you need to find the offending circuit. I bet you find the issue before you get this far though.

 

YouTube parasitic draw and test it. I’m dealing with this on my girlfriend’s jeep and can’t figure it out. Have a few circuits drawing power when off but inconsistent.

 

take it to advance, or napa....have battery tested, go from there

 

Very Modern cars often have significant parasitic draw after shutting off the car for up to 1 hour. Modern electronics also wake up from time to time. Finding a parasitic problem can be a big problem.

Disconnecting and reconnecting the battery to put your multimeter in-line to test for parasitic draw is not the best way to find the issue in these very new cars it seems. Better is to take the voltage reading at the fuses and using a chart (found online), calculate the draw. This way you can let the car sit for an hour and the car's systems should have shut themselves off by then.

Our 3rd gens don't have this issue, but I don't know the year of your Jeep.

 

On my 2000 I had a similar issue. Turned out to be the factory amp for the stereo was bad and was draining my battery. Removed all factory stereo and amp and went aftermarket and that solved it.
Took a lot of testing systems but that was it.