Power Wheels are replicas of real-time cars, trucks, motorcycles, vans and jeeps. They are made by Fisher Price and accommodate children from toddler-sized to 6-7 years of age. Power Wheels are run off different sized rechargeable batteries. The common battery sizes are 6-volt, 10-volt and 12-volt. Each battery comes with its own type of special connection. One popular type of Power Wheels vehicle is the Jeep Wrangler, which uses a 10-volt battery. In order to modify it to take a larger 12-volt Power Wheels battery like the ones that fit inside the Power Wheels 4 X 4 pickup truck, you need to do some rewiring.
Connect the Power Wheel 12-volt wall charger to the 12-volt Power Wheel battery and allow it to charge for a full 18 hours for the first charge. Every charge after that should be 14 hours.
Open the bonnet of the Power Wheels Jeep and use a screwdriver to remove the two screws holding the plastic engine manifold in place to reveal the battery.
Pinch the tabs in on the plastic wiring harness and unplug the old 10-volt battery inside the Jeep. Remove the battery.
Use wire strippers to snip the end of the wiring harness that runs from the Power Wheels Jeep.
Grasp the 12-volt battery connector end and then strip about an inch of wire from both the positive and negative cables. Wrap the end of the positive cable on the 12-volt connector to the wire running from the Power Wheels Jeep. Do the same thing to connect the negative wire to the 12-volt connector and then wrap both connections with electrical tape.
Place the fully charged 12-volt battery into the Power Wheels Jeep and then plug the wiring harness into the battery.
Replace the plastic engine cover and screw in the two retaining screws.