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1946 Jeep CJ-2A Rewiring Made Easy

Posted in How To: Electrical on August 2, 2018
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It doesn’t get any better than bringing your project Jeep’s body home from the paint shop. This technically means you’re rounding third base on the restoration and heading for home plate. But before those seats go in and the fenders go back on, there are some important items to be installed first—the wiring harness and fuel delivery system, for instance.

Keeping the gremlins away from any project sometimes means completely replacing these key drivability and reliability systems to get it done right the first time. Here’s where Walck’s 4 Wheel Drive scored big points with us. Walck’s is a one-stop shop for Jeep restorations, and among its many offerings is a high-quality 2A Wiring Harness made specifically for that Jeep’s lighting, horn, and accessory systems. A steel reproduction fuel tank for the 2A is also available through Walck’s.

The Walck’s period-correct wiring harnesses are custom-made for each Willys Jeep application and come with all the correct-size eyelets, covers, and connectors ready to go for easy installation. Walck’s also has whatever else you might need to finish the electrical aspect of your project, such as voltage regulators, amp gauges, firewall grommets, and even 6V generators. We added an N.O.S. Sterling “Made in USA” 6V regulator Walck’s had in limited quantities to our shopping list, knowing it would add to the vintage appeal of the engine compartment. A new OE-style Olaco reproduction steel fuel tank, as well as the sending unit with brass float, fuel gauge, and steel lines were also ordered up to make sure we didn’t have any issues with rust or any other particles that can cause problems in your fuel lines or carburetor later.

Taking your time and thoroughly reading the supplied installation instruction sheet supplied with the Walck’s wiring harness before diving in will certainly keep things going smoothly and help avoid any wire routing or costly hookup mistakes. Also, when moving to the fuel delivery system, make sure to pre-check the hard line male and female fitting going into the bottom of the fuel tank prior to installing it in the Jeep, as you will likely need to clean some of the paint out of the threads to get a leak-free seal. If you install the tank first and then try to check the line fitment from the bottom of the Jeep, it will be a lot harder than if you have it on a waist-high worktable directly in front of you to clean out the threads.

The best part about this chapter of our ’46 Jeep CJ-2A build is that we didn’t have to be an electrical engineer to tackle the install. Walck’s 4 Wheel Drive made it easy. Check out the following photographs for the major steps, and some tips and tricks we learned along the way, as we installed the wiring harness and fuel system on our nearly finished project 2A.

Walck’s 4 Wheel Drive delivers the completed wiring harness along with detailed instructions that clearly identify and label each portion: main harness, right side harness, chassis harness, headlight harness, and so on. It also comes with numbered terminal ends.
This new OE-style reproduction steel fuel tank, a new brass float sending unit, and fuel line kit were chosen to help us avoid chasing down any fuel line clogs and carburetor issues in the near future. Note: the shorter flex and hard lines used on either side of the fuel pump are not shown.
Assembling the headlight wiring harness is easiest prior to the front grille being installed. We made sure the smaller terminal ends went up into the rubber grommet first and then the ground wire can be screwed in and the plug installed securely.
As shown here, we routed the right headlight wire loom along the top of the grille and then attached it to the stock locations with the supplied clamps. The left side will then join with the right loom at the top corner of the grille and be routed together going to the fender junction.
We chose to put the firewall grommet onto the right side wiring harness and then went ahead and mounted the grommet into the firewall.
Once the main wiring harness and right side harness are carefully routed with all the underdash terminals in place, you can start permanently attaching the wires per the instructions that are color coded with tracer markings like the keyed ignition switch shown.
Make sure to carefully tag and label the wire terminals and then route them to the proper gauge location. Many of them look very similar in color and could have the same tracer markings.
To make life easier we were able to attach all the amp gauge wires out in front of the dash opening. Then we carefully fed the wires back through the hole and attached the dash mounting bracket from the rear, securing with the supplied hardware.
Familiarizing yourself with the headlight switch markings and matching them up with the instructions beforehand is a good idea before making any connections.
Once you’ve reviewed the markings on the headlight switch and the coded colored wires, you can easily attach them under the dash as shown per the instructions. Mount the switch from the back of the dash and then secure the cap nut and finally the threaded knob back onto the front of the switch.
This new harness from Walck’s deletes the separate stock dash light switch that originally came in the Jeep, and the dash light now goes on at the first marker light detent (obviously with the headlights). Make sure to have metal-to-metal contact on the back of the dash where the nut and star washer secure the light for a good ground, as with anything with only one wire.
Once the marker lights are installed with the loom running along the bottom of the grille, you can then attach the headlight leads from the main harness to the headlight and marker lights at the junction block as shown. Again, make sure to have metal-to-metal contact on bottom of the grille where the marker light nuts secure them for a good ground.
We decided to restore and use the original high beam indicator switch, as it looked to be in decent condition. After installing it in the floorboard, we then attached all wiring terminals per the instruction sheet as shown.
These bullet end connections for the rear brake and taillights from the chassis harness to the main harness and the surrounding wiring lengths exemplify the quality and craftsmanship of the Walck’s wiring harness.
Moving to the rear of the chassis harness, we soldered the wires coming from the left taillight assembly together, and then after using heat-shrink tubing we covered it with the loom for even more protection before securing it to the frame. We are using a 1946-style right rear reflector setup currently, but still routed the Right Taillight/ Brake light wiring harness and wrapped it up for future use with no issues.
This N.O.S. Sterling 6V voltage regulator from Walck’s became available on a limited-supply deal, so we bought it on the spot. The unit is from the 1960s, and it is a quality piece that is made in the USA and will certainly help to keep the 6V electrical and charging system working well.
We connected the voltage regulator to the generator wiring harness per the instructions. We also used a strap from the generator to the block to aid the charging system grounding. Per the instructions with the regulator, once you have all connections made along with battery power (but before you start the engine), you will need to polarize the generator by momentarily touching a jumper wire from ARM to BAT terminals on the regulator and you see a spark.
Moving onto the fuel system, we installed the new rubber fuel tank neck grommet. Reusing an older one that is likely more brittle and prone to cracking might lead to fuel leaking into the tub.
At this point you can decide if you want to use anti-squeak factory felt, but remember that thicker felt can retain water, so we opted for a much thinner felt we found just to keep it off the tub floor a tad. Install the tank as shown using a bit of lubricant on the neck and secure with the factory-type straps. The rear strap acts as a ground, so make sure to have metal-to-metal contact to the tub.
Once the sending unit was attached to the fuel tank, we routed the sending unit to the fuel-gauge wire and secured it to the top of the sending unit.
Having a friend help you maneuver the longer hard line correctly from the bottom of the tank through to the engine compartment will help. After attaching the “pre-prepped” fitting at the bottom of the tank, you can work your way forward securing the line along the inside of the frame and at the front of the tub as the images show. Finish the fuel system by attaching the flex line to the front of the hard line and over to the inlet side of the fuel pump, and the small hard line from the outlet of the fuel pump to the carb.
To top it all off, we also ordered a new fuel tank cap from Walck’s to keep things sealed and leak free. This satin black unit was just what we were looking for, as it matched a lot of our trim pieces.
Once you have completed the wiring harness installation, hopefully you are able to get a reading like this (almost +25) on the amp meter. If it stays there when you pull the light switch on, then your 6V generator and voltage regulator are likely doing their job and charging the battery as you drive. You can also test with a voltmeter directly at the generator while the engine is running to see the output. We were at about 10.6 volts and now good to go.
Lastly, before hitting the road (and trail), it’s time to check out and resolve any possible connection or grounding issues you may have with headlights, marker lights, tail and brake lights, dash light, and high beam switch and indicator.


Walck’s 4 Wheel Drive

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