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JeepEV: Electric Vehicle Conversion Project
12 volt Wiring



12-volt Power Connectors:

     For all the 12 volt connections, I wanted to retain the weatherproof connectors that came with the Jeep. Since I sold my wiring harnesses with the engine, I had none of the old ones. I was finally able to track down some GM style connectors in 2,3,4,5, and 6 pin styles and used them for most of the 12 volt wiring. I also used many of the solderless crimp style connectors for splices and single wire connections.

12-volt Wiring Page Photo
GM style weather-pack plugs make good solid connections.



12-volt Power System Protection:

     The Jeep has four main 12volt power lines that power the ignition, upper fuse block, lower fuse block, and engine compartment relays. The old fusable links were removed with the old wiring harnesses, as they were built into them. I had to install some new form of circuit protection for the 12-volt system mains. Because all of the main lines would require large fuses, and I didn't want to install a new fuse box or spend a lot of money, I decided instead to use the packaged fuseable links which Buss makes. I installed three of these fuse links on a small wood block on the driver's side wall of the engine compatment. These three links are 60A, 50A, 50A, links which power the two halves of the inner fuseblock, and the engine compartment relays respectively.

12-volt Wiring Page Photo 12-volt Wiring Page Photo
You can see the fuseable links mounted to a small
block of wood to isolate them from the chassis.

     For the wire that powers the ignition switch (and any loads connected to it), I used a Buss 100-amp circuit breaker. It is resetable and waterproof. I also used a second Buss circuit breaker for the power steering pump. This one is a 80-amp, automatically resetting model. I mounted both of these breakers on the passenger's side wall of the engine compartment. The reason why I didn't use these breakers for the other mains wiring is because they are pretty expensive, whereas the fuseable links aren't.

12-volt Wiring Page Photo
The two circuit breakers are mounted to the
passenger's side engine compartment wall.



Turn Signal modification:

     The Cherokee has two clear lensed lights that face forward and two yellow lensed lights that face to either side on the front. The clear lensed lamps act as parking and turn signal lamps, and the yellow lensed lamps are side-marker (parking) lamps.

     This configuration always bothered me a little because it was hard to see the front turn signals unless you were looking almost straight at them. So using three 5-pin relays, I wired up a circuit that makes the side marker lamps blink when ever the turn signal is on. Here's the tricky part: the side marker lamps must function in two separate ways depending on if the headlamps/parking lamps are on or not. That is, when power is comming down the turn signal circuit, the side-marker lamps must be in the following state: If the parking lamps are OFF, the side-marker lamps must turn ON. If the parking lamps are ON, the side-marker lamps must turn OFF. This means that when the parking lights are on, the side-marker lamps appear to flash "opposite" from the normal turn-signal lamps. (pictures to come).

     To achieve this effect, I had to use three 5-pin relays. One relay to sense when the parking lamps are on, the other two to make the side-marker lamps blink when the turn signals are on. I mounted these relays on the firewall above the power brake booster. You'll notice there are four relays in the picture, the fourth one is for the vacuum pump.

12-volt Wiring Page Photo 12-volt Wiring Page Photo
The three relays are mounted to the firewall, and
here's the schematic for the turn signal circuit.


Remember, More photos are in the Photo Gallery!