62 CJ5 Ignition Meltdown

[Lyle462]

Just bought a 62 CJ5 last month. 4-134F engine with a 12 volt conversion (solid state ignition). Just trying to find out exactly what I have here. I've been driving the jeep off and on just around our small town for a few weeks now. Yesterday I smelled electrical smoke while driving. Smoke then started coming out from under the dash. Vehicle died and I turned the key off. After reviewing I noticed the ignition wire from the ignition switch itself to the positive side of the ignition coil had melted. I've since separated the wire bundle to see how bad the damage is. I noticed where the ignition wire goes from the ignition switch to the instrument cluster (H terminal of the cluster) had also melted. Basically both wires at the cluster melted. the one going from ignition to cluster and the one going from the cluster to the positive side of the ignition coil. The coil has an external resistor. I'm discovering several oddities with the wiring and I do have the correct wiring diagram from the service manual. Of course the manual is for 6 volt ignition I believe. I'm trying to find out what I have in terms of alternator and what not. I researched the OEM Technology number in hopes to find a wiring diagram but no luck there. Also, (see pic) there is a terminal/box/voltage regulator looking object on the firewall. I was guessing the alternator must have an external regulator and that is what the box on the firewall is for but I want to be sure if I could find what type alternator I have.
I also noticed (per wiring diagram of the distributor) that the BLACK wire from the distributor should go to the ignition side of the ballast resistor IF you have an externally resisted coil which I do. This coil's BLACK (positive) wire was attached to the positive side of the coil. Not the resistor. Yet another reason why I'm trying to find what type of alternator I have. I thought it looked odd that the red wire from the alternator was jumped (per the pic) and they had attached the other wire from the alternator to the negative side of the ballast resistor. I've got a bit of a mess here but did purchase the Jeep maintenance manual which has a wiring diagram. It might be awhile before I get this old gal safely back on the road297729782977298029822983

[LarrBeard]

Your best bet is to try to trace back to who did the conversion. History has proven that just about every 12-volt conversion ends up being a custom conversion.

You may end up with a roll of wire, some terminals and then take the parts you have and start over rather than try to figure out just how the last guy rigged it.\

Let us know how it goes.

[Lyle462]

Looks like the conversion was accomplished several owners ago. So much so that the gentleman is deceased now. I bought another ignition switch and basically made up an ignition and starter circuit. I just wired it all externally. Stood there beside the engine bay and started the thing this afternoon. I let it run for awhile and everything looked good. I thought about checking voltages but since I don't have lights, heater, etc... tied in yet I did not check. Spent the rest of the afternoon digging around under the dash. Instrument cluster, light switch and things like. Just checking how they are wired in relation to the wiring diagram in the manual. There's a few things that don't make sense to me. A lot of items wired into the IGN post of the ignition switch. The ACC post was all but empty. I know NAPA really loves me now after buying all of the wire and connectors I'll be needing!

[LarrBeard]

One of the little "free" Harbor Freight multimeters is all you need for Jeep work. It is most useful for checking that wires go from here to there with the beeper. Get a good set of crimpers and wire strippers to make sure that terminals are properly crimped and don't try to make one size terminal fit everything.

Your one step at a time approach is good. get it to start and run. Make sure the battery charges. The horn goes direct to the battery - so you don't have to turn on the ignition to warn someone. I don't know if the conversion added a circuit breaker panel, but since you've seen the results of what one short circuit can do - maybe add a small breaker panel in the rebuild.

Then, document what you do. Write it down as clearly as you can - because you will forget chicken scratches in a couple of years.

And, if you have questions - ask! We're full of opinions and info.

And, when you are done:

A. You will have a good, solid reliable Jeep, and;

B. You will have learned a whole bunch about things you never thought you would.

[Lyle462]

Thanks a lot for the advice. I do have a pretty decent Fluke meter. I used it to check my new ignition switch before I made up the start/ignition wiring test run. I wanted to be sure the start, IGN, ACC and BAT positions powered (and did not power) what I wanted, when I wanted. I'm wanting to add a fuse block and to make sure I'm using the correct gauge of wire for the various circuits I want to protect. Normally I guess a person would go by what was previously installed but I don't trust that. Especially after what I've found already. This jeep is pretty basic and I want to keep it that way. I'm figuring the fuse block should have an ignition switch, horn, head/tail light switch, hazard flashers/turn signals and wiper circuits. Then an inline fuse for the heater. I have no radio nor do I want one. No cruise control or any of that sort of stuff. Just a basic ole 62 CJ5. Now that I know I have a reliable start/ignition circuit, I've started on a wiring diagram. By the way, this jeep has a starter relay on the firewall (part of the previous 12v conversion I guess). It's the 4 post type.
3012

[Lyle462]

Just finished the rewire today. I learned a lot! The previous owner did not have a fuse block installed. I added one for ignition, hazard flashers, vehicle lights, running lights, wipers and the horn. Added inline fuse for fuel sending unit and replaced wiring and fuse (no more glass type fuses) for heater. I took a few liberties with the instrument cluster as well. Don't know if it's perfect but it's darn sure better than it was.

[LarrBeard]

See, now you are an expert in how to rewire a CJ5 (that means you have completed a project and it works to your satisfaction). I suspect that the in-line fuse for the fuel sender was a bit of an overkill, but - what the hey - it's your job and it works.

Make a good record of what you did, with a lot more notes than you think you would ever need. Since you've done a good job, it will be a long time before you get back into it and by then you will have forgotten something!

And, when the next guy asks about a rewiring job - share your "expertise" with him/her.

[Lyle462]

Believe it or not, I did enjoy doing this rewire. Wouldn't want to do it again real soon but I did learn more than I thought I ever would. In regard to writing everything down, YOU BET! I saved my wiring diagram to a memory stick along with a view of the back of the speedo and instrument cluster. I installed a new ignition and light switch. Logged how that was all wired as well. I learned the fuel tank sending unit is bad but that will have to wait for another payday down the road.
I was curious about wrapping my wire bundles. Any advice on what is the best thing to use? I can get the standard bundle wrap from my local NAPA store but wondered if there was anything else better. Thanks!

[gmwillys]

The worst part is getting into a position to where you can see and get your arms up under the dash. The military was smart when they had the instrument panel to where you can pull the whole assembly. M38A1s you could pull the entire dash out, along with the cluster. I don't remember if the 5s did as well? A CJ2A-3B, you had to do all the work laying up between the seats, and around the shifters.

I like to use a good quality electrical tape, and wrap the harness much like a modern factory harness. The old cloth harness covers worked just as well, but would often attract moisture. The new wiring harnesses that utilize the original looking fabric covering are backed up with modern wires with good covering, so they are not subjected to moisture intrusion.

[Lyle462]

Yep. I ended up taking both seats out and just lying on the floorboard. This dash doesn't come out. Doesn't look like it was meant to either. That would have made things a little easier for sure. Thanks for the advice. I will follow suit.

[LarrBeard]

Any advice on what is the best thing to use.

Tape works. There is a spiral wrap. Tie wraps.

Lots of choices and all are better than melted and burned.

[Lyle462]

Thank you!