Our 2008 2 door Rubicon JK has had what appears to have a very small battery drain since new. Dealer has told us several times that it’s normal, but it will run the battery down in a month if not driven or kept on a battery render.
A few months ago, I tried to isolate the drain by disconnecting the battery +cable from the battery and pulling fuses, to no avail, except…I accidentally “sparked” something and now some of the dash and annunciators are inop. I checked all? the fuses again and no blown ones.
Anyone have any ideas before I take it to a shop?
Thanks in advance for your collective knowledge and expertise.
Battery drain issues can be tricky to diagnose, especially if it’s been going on since new. Here are a few suggestions that might help you further isolate the problem:
Parasitic Draw Test: Since your dealer mentioned it’s normal to have some drain, it's worth measuring the parasitic draw. You can do this with a multimeter by connecting it in series with the battery while everything is off. Ideally, the draw should be under 50mA. If it’s higher, you’ll need to continue isolating the circuit.
Check for Undocumented Accessories: Sometimes additional accessories (like aftermarket radio or lighting) can be the culprits if they've been installed improperly. Make sure to check for any modifications that may have been made.
Resetting Modules: After the spark incident, you may need to reset some of the electronic control modules in your JK. Disconnecting the battery for a few minutes can sometimes help reset some systems, but if that doesn't work, a dealer or shop with a scan tool might be able to reset them more effectively.
Check Ground Connections: Loose or corroded ground connections can cause various electrical issues. Inspect ground points, particularly under the hood and near the battery.
If all else fails, it could be worth having a professional shop with experience in JK models take a look, especially since they've got the right tools to diagnose electrical issues effectively.
Good luck, and keep us posted on what you find out!