2018 Jeep Wrangler JKU Replacing the Battery Part 2, by Jon Jebus on YouTube. 1 min 43 s.
- Video length
- 1 min 43 s
- Time to do it
- 30 minutes
- Difficulty
- Easy
- Steps
- 9
What you need
Steps
Park on level ground, switch the engine off and let the battery area cool. Put on safety glasses and gloves, since old batteries can leak acid.
Disconnect the negative cable first, then the positive cable, and lift the old battery straight up and out of the tray.
Wipe the battery cradle and surrounding tray with WD-40 so the surface is coated and less inviting to mice.
Spray WD-40 into the corners and gaps of the engine bay where mice nest, plus the entry points they use to get in.
Clean the new battery posts and the inside of both cable ends with a wire brush until the metal is bright.
Lower the new battery into the tray with the terminals on the same side as before, then tighten the hold-down clamp so it cannot slide.
Bolt the positive cable to the positive post first and tighten it, then fit the negative cable to the negative post.
Push the covers, brackets and loose wiring back into place so nothing sits on the battery or rubs on the terminals.
Start the Jeep and take it for a short test drive to confirm the warning lights and error codes stay off.
Tips and common mistakes
Always take the negative cable off first and put it back on last, so a slipped wrench cannot spark against the body.
Keep WD-40 off the battery posts and cable ends, and use dielectric grease there instead.
Reapply the WD-40 every few months, because the smell fades and mice come back.
If warning lights stay on after the drive, check that both cable clamps are tight and clean before anything else.
Questions
Do I need to reset anything after fitting the battery?
Most JKU error codes clear themselves after a normal test drive. If a light stays on, recheck the terminal clamps for tightness and cleanliness first.
Does WD-40 really keep mice out of the engine bay?
It can help for a while by making surfaces unpleasant to walk on and masking nesting smells, but it is not a guarantee. Reapply it and remove any nesting material you find.
Which cable goes on first when refitting the battery?
Positive first, then negative. That order keeps the wrench away from grounded metal while the circuit is still open.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
