12 volt conversion

I am getting ready to do a 12volt conversion on my 51 Willys cj3a. This is a straight offroad vehicle so performance and the best waterproofing are in mind. What luck as far as wiring harnesses, gauges, coils, distributors and alternators have you all had ?

 

A couple of ways to go at it, first you will need a charging device, an easy swap and most common is a Delco 10si alternator, some fabbing of mounts are required but a simple hookup. Then comes the gages and lights, You could go with a voltage resistor to step down the voltage from 12v to 6v but most people swap them out. Switches like headlight ignition don't care if 6v or 12v. The starter can be replaced with 12v but if you don't crank for a long period it will last a long time without replacement. Then there is ignition, the points are the same 12v or 6v so no problem there but the coil will need to either have a resistor to step down the voltage or be replaced, if 12v coil you will need to either get an internally regulated coil or get an external regulator for the coil. An good upgrade for reliability is a Petronix upgrade for the distributor to eliminate the points.

 

New to the board, but I just did a 12 volt conversion on my 52 3A. Please let me know if you have any questions or run into any problems. Everything that LarryD said is very good advice.

 

Thanks Guys I should start the process in the following weeks.

 

Does that alternator fit the L-heads? I'm swapping over the original generator to an alt.

 

I am still trying to figure out how to wire all my stuff (lights and other stuff) when I did my conversion, of course, I have NO EXPERIENCE wiring cars, but have wired a few barns. It goofs me all up. The hardest part about it is where to run the wires so that the battery is always charging. I have a video of how to do it on my YouTube page. I can post it later.

 

wiring a 110v light is similar to wiring a 12v light the difference is 110v uses an insulated common. In 12 v you use the ground in place of the common. The light is grounded to the body the body is connected to the frame and the frame is connected to the negative terminal on the batt thus completing the circuit. To wire a light go from the switch to the light and ground the light fixture.
There are volumes on wiring the alternator and many opinions about 1 wire v 3 wire but here's what I have, It's simple and it works. On the back of the alt put a short wire from the #2 pigtail terminal to the batt terminal then a 10 or 8 ga wire from the batt terminal on back of the alt to the solenoid. It goes to the same terminal the positive battery terminal is attached to.

 

You will need to modify the bracket or fab one, there are kits on the market also.

 

Here is a wiring diagram on the cj3a page.

Thanks guys for the help

 

yeah I have several wiring harness diagrams, for all the jeeps from '45 to late 60s, the problem is half my wiring harness I bought NOS, and the other half I am doing a lot of custom stuff to.

its a 1949 Jeep Pick-up. I have the diagrams, but I am doing something different with the wiring.