Adding Power Seats to Your Jeep Grand Cherokee

My Jeep didn't originally have the power seats but it appears to have the wiring at the fuse box. According to Jeep owners some Grand Cherokees came from the factory pre-wired for extra options. If your Jeep happens to have wiring for these extra options consider yourself lucky, my Jeep unfortunately was not pre-wired for any options. To check for the extra wiring look under the carpet under your seats for the power seat harness connectors. If it looks anything like the picture below then you don't have the connector, it is normally taped to the harness.

Since I wanted the power seats to work in my stripper Jeep I started some detective work. The first step was to begin searching at the fuse box at the passenger's side of the dashboard. Looking at the fuse box I could see the wiring going into the slot designated for power seats and wiring on the side exiting the slot.

There is 12V at one side of the connector in the fuseUsing my multi-tester I found 12 volts on one side of the fuse box and a solid red wire leading out of the other side. I traced the red wire to a connector on the driver's side of the dashboard. It is a large connector above the brake pedal on the firewall. Here you can see both sides of the connector. The female side is attached to the firewall and the male side is what comes from the fuse panel.

Once I found the connector I backprobed the wire I thought to be the correct one for the power seats. In order to determine if it was the correct wire I put a fuse in the slot, set my multimeter to show 12V, and removed the fuse. As soon as the fuse was removed the voltage disappeared. This indicated that I had the correct wire.

Since my Jeep was missing the rest of the harness I needed to build my own to get power to the seats. Rather than deal with inserting wires into the female connector I tapped into the wire coming from the fuse box. Taking the 12V from that point using the correct gauge wire I ran it down to underneath the driver's seat.

Mimicking the factory wiring I then took the 12V wire over to the passenger's seat. The power seat circuit is normally protected by a 25 amp automatic circuit breaker (ACB). An ACB is convenient because they will automatically reset if tripped. Say for example both seats are moved all the way back at the same time, once the seats reach their stops the current through the circuit rises sharply. If a fuse was used it could blow and the owner would be without power seats until a fuse was found.

Unfortunately for me I could not find an ACB, I have been using a 25A fuse in it's place and carrying a spare just in case. So far after 6 months the fuse has not blown. The seat wiring is grounded to the body of the vehicle just below the seats in the same way the factory did installed their harness. The diagram below gives a detailed explanation of the wiring harness and how everything is connected.