Proposed wiring diagram for review

It may be better to run the 8ga battery charge wire to the pos. on the starter solenoid rather than inside through the ign. switch. Keeps the wires shorter and will not take up much space on the ign. switch that will already have a ton of wires in that area.

 

OK here is one more try.
Thanks for your patience on this. Hope this may help someone else in my position.

 

This is looking better, IMO. At the risk of becoming annoying, just a couple of further notes:

1. It's not clear in your diagram, so just to be sure you know -- some starter solenoids have a separate terminal which provides +12V when the solenoid is engaged. If you have this kind, the wire from the starter to the coil+ should connect to it.

2. The inline fuses connected to the switch should be at the switch end of the wire. There's still a lot of current available here and the 14ga wires are protected by the fuse. The less wire between the source and the fuse, the less chance of that unfused wire shorting to ground.

3. If it were my project, I'd probably look at mounting the junction point near the battery, under the hood. But then my rewiring fantasies are a bit more ambitious. This way, fusible links might not be necessary except in the wire feeding the ignition switch. On the other hand, fusible links are cheaper than fried wiring.

4. I think the alternator's #1 terminal (wired through the "idiot" light) should connect to the IGN terminal instead of ACC. There's no need to "turn on" the alternator if the engine won't be running anyway. Also, I don't think you want this light coming on in the accessory position.

 

OK, just one more, then I'll shut up.

The simplest way, as suggested by Jason, would probably be to use the starter terminal as the junction point. Something like this:

Heavy (battery) cable from battery + to starter +. Fusible link from alternator's BATT terminal to starter +. 14ga wire from alternator's #2 terminal to starter +. Fusible link from starter + to ignition switch BATT terminal.

The fusible links should be about 5-6" of 12ga fusible link wire spliced into the needed length of 8ga wire, again with the fusible portion near the power source.

 

Good thread, subscribing so I can come back and read more when I'm more awake.

 

What is the "idiot light?"

 

There are 2 "idiot lights" on the typical jeep speedo:



One just above the "amps" and one above the "oil"

They are called "idiot" lights because they don't tell you as much information as a gauge will.

 

Thanks. I knew about the lights, but had not seen that reference before. I like it, even though I like the lights. I just noticed how old this thread is. burnzee, how did you make out? I too have a bastardized wiring system that I am trying to sort out, so your wiring diagram has helped me. The stock wiring diagram is no good to me.

 

You do not want to run your #1 wire to the ign terminal. If you do the alternator may feed back to your coil and the engine will keep running even after you shut the ignition switch off. Stick with the ACC terminal.

 

My #1 wire runs to the ACC terminal, but it goes through the ballast resistor. Is this correct or should it go directly to the ACC terminal?

 

The #1 terminal should go to the charge indicator lamp. The other side of the charge indicator lamp should be connected to the IGN terminal on the ignition switch.

The charge indicator lamp will generally not pass enough current to keep the engine running, unless you have an electronic ignition.

If it does run on, you need to add a diode to prevent the backfeeding. A diode is a good idea anyway, just to be sure.

Of course, you can connect to the ACC terminal. The downside of this is that the charge indicator lamp will be lighted in the ACC position, drawing power from the battery for no reason, unless you like having this light to remind you the switch is ON.

If you wire directly to the ACC terminal without going through the charge indicator lamp, you will be energizing the alternator's field in the ACC position, when the engine is not running to make use of it. This will drain the battery even more quickly, and with no benefit.

If you don't run through the lamp, you can substitute a resistor. Just to be clear, this is not typically called a ballast resistor, though it does pretty much the same thing as a ballast resistor. But when you say "it goes through the ballast resistor", it suggests you're somehow connecting to the ignition coil's ballast resistor, which would not be right.

 

If I understand correctly, shouldn't there only be one wire going from the coil to the ballast resistor to the IGN terminal? What wire do you have going to your ignition coil?

 

Good stuff, guys. Thanks.

CO64CJ5, based on your comments my current set-up now makes sense. The PO was bypassing the idiot light because he had put in a voltage gauge. So in the absence of using the light he was routing the #1 terminal through a resistor to the ACC terminal. I called it a ballast resistor, but I’ll defer to you and just call it a resistor. It is bolted to the firewall in the engine bay (white with 4 prongs on it). I assumed it was the ballast resistor from my research, but perhaps the PO got rid of the BR because I can tell you that he had 12v wired directly to the ignition coil in the RUN position on the ignition switch, which I learned was a no no. The coil might be able to take 12v all of the time, but I need to pull it to check for fine print. I doubt it as it looks like it could be the original coil.

My plan is to eventually hook the idiot light back up, so I’ll remember to wire it as you instructed. I don’t plan on using the ACC terminal much if it all, so I’m not worried about draining the battery and I do like the idea of having the light come on when the key is turned to ACC as a reminder.

If I were to move the #1 terminal to the RUN (not START/CRANK) position on the ignition switch, what, if anything, would I wire to the ACC terminal because right now the #1 terminal is the only thing wired to it?

EricM, for the record I have not gotten this engine to fire yet, so I thought I was on to something here. The PO wired 12v directly from the IGN terminal (RUN position) to the coil WITHOUT going through a ballast resistor. So I was going to splice that wire and route it through the BR. I thought I could do this since the resistor has 4 prongs on it. Is the ballast resistor inline, or perhaps I should use a resistance wire?

What’s weird is that in addition to wiring 12v directly to the coil from the ignition switch, the PO did not wire the I terminal on the solenoid to the coil. It’s not being used at all. So upon cranking the solenoid activates the starter motor and then the coil gets the constant 12v from the ignition switch. I have since unhooked the wire from the ignition switch to the coil and added a wire from the I terminal on the solenoid to the coil, but still no spark. I put a voltmeter on the coil and can get 12v across the coil to the distributer in the RUN position, but perhaps it is not energizing correctly when cranking. I think I need to replace the coil. The distributor cap I noticed is brand new.

 

When your Ign switch is in the crank position, there is no power being applied to the IGN terminal on the switch. That is why you need a bypass wire to the pos terminal of the coil. You can easily test this by connecting your test light to the negative terminal of the coil and ground and crank the engine. The light will flash telling you that you have power on crank and also that your breaker points are functioning.

 

Thanks, Walt. Yes, that is why I got so excited when I saw that the bypass wire from the solenoid to the coil was missing. I thought I had found the problem. So I wired it and gave it a crank with no success. Needless to say, disappointing. However, I push forward! Once thing I haven't done yet is test the coil when cranking as you mention. That's next plus I am going to check resistance on the coil. The distributor cap is brand new, the coil is most definitely not. So my current thought is that the coil is bad. Hopefully I'll know soon. I need to hear this baby hum so that I can celebrate with some

 

There's no single "right" way to do it. If you like having the "AMP" light on when the key is in that ACC position, the only down side is the added drain of that lamp -- pretty insignificant.

Normally, the ACC position would be wired to radios, GPS, sound system, etc. Stuff you want to be able to power without energizing the ignition system.

If you see 12V on both sides of the coil, at least the coil is not "burned out", thought it could still be shorted internally.

If you use a jumper wire to briefly short the "-" coil wire (the little one going to the distributor), you should get a spark if the coil is good. If this works, it may be that your points are not closing, or that the distributor is not grounded adequately.

I think with at least some ignition switches, there is power on the IGN terminal while cranking. If you're getting power on the coil while cranking, you're OK.

On my '64 CJ5 (F134, 12V), I don't have a ballast resistor. The coil is fed directly from the ignition switch and there's no "I" output from the solenoid.

 

If you don't have a ballast resistor then you either have to have an in-line resistive ignition wire or a coil with a built in resistor. If you don't have one of these, then you are running full 12V to the coil all the time which will shorten the life of the coil and the points.