Saturday Wiring Puzzle Cj3b With V6

Hey CJer's

So after 10 months of toiling and troubling (and having fun) I've almost reached the end of my CJ3b restoration. I'm waiting for a few final things to be completed before writing the project up and posting pics etc. The jeep is running well and goes like sh#t off a shovel with the buick V6 but my last (I hope) little dilemma is the wiring.

I made some pretty spaghetti-junction type wiring diagrams when I dismantled the jeep so that I could re-wire it the same way as I found it, which I have now done. However i've got a parasitic draw of about 3 amps with the key in the off position and even the amp gauge jumps to more discharge when I turn the key to the on position. This obviously flattens the battery when the jeep isn't running so I have to disconnect the negative cable from the battery after every use.

I have been checking online diagrams/sources/forums etc to try and figure out if my wiring setup is correct or not but I haven't had much luck figuring it out... mainly because i'm a total amateur with electrics and also because its a CJ3B converted to the Buick 225 V6 with mechanical oil and water gauges, amp gauge and an added fuel gauge on the dash (I think the speedo fuel gauge must have broken in the past). Generally it seems there are so many variations of the wiring setup potentials that i've become totally confused with it all. I've checked and double checked for anything obvious that could be grounding out and causing the battery draw but all the wiring looks well insulated and protected so my last hope is that someone here might be able to check my new and improved (but still quite messy) wiring diagram as the jeep is now wired and tell me if there is anything clearly incorrect and might be causing the draw?

Here's a link to the wiring diagram: IMG 0168

Looking forward to writing the project up in full and getting final pics posted so that I can give back some to the forums after alot of taking!

Thanks to all.

Note that I have not yet wired my 12v electric horn, wiper motor or heater blower... any advice on the best way to add these in would be awesome

 

Does this work? IMG 0168

 

I just draw it in my mind. I seem to be rewiring every Jeep I buy these days though.

 

I wish I had your knowledge Daryl! Let me know if you see any mistakes with my wiring.
Thanks
Oli

 

I don’t understand electricity but I’d disconnect things one at a time (gauges, senders) and see if one of them makes the leak disappear.

 

This.
And start with the ammeter. I've had nightmares in the past caused by el cheapo ammeters.

 

Thanks Doug! It's an original looking ammeter i.e. well built but i'll check there and let you know. Thanks

 

From your drawing, it appears that your alternator is powered all the time causing a current draw. The one connection on the internal regulator should be powered from the accessory side of the ignition switch.

 

The blue wire from the alternator is the exciter wire, it needs to be switched. depending on the ign switch it needs to be connected to the ignition side of the switch or if car doesn't turn off try using the accessories side. To test, unplug the alternator if the draw goes away that should be your problem.

 

I would second the ammeter check....or just get rid of it altogether and install a volt meter. Looks like you've got an internally regulated alternator?...whats the output rating?

As you've alluded to there's many ways to skin this wiring cat. I think it partially depends on how many additional accessories you want to install and what your highest possible draw will be. It also depends on if you're trying to keep it original-ish. So....

Here's some ideas:
---Ditch the ammeter and put in a volt meter (several ways to wire this in)
---Use the ACC terminal of the ignition switch for ignition-on accessories or anything you want key-on activated without activating the ignition circuit (stereo or gas gauge for example)
---I usually add in extra stuff (lights, winch, air compressor, heater, cooling fans etc)..So, typically on an older truck I start by converting to a high-output internally regulated alternator with upgraded battery and charge cables (2-2/0awg)...and a volt meter, no ammeter, but you'll have a charging warning light if you want one.
---Protect your circuits with either breakers (pretty convenient for large/major wires/cables) or fuses.
---Make sure you have really good grounds.
---Use shrink tube for your splices and terminals
---Use the correct size wires for the amp draw on any given circuit
---Know the amp draw of all your accessories
---Add an auxiliary circuit for accessories with an aftermarket fuse box as the major junction point (headlights, off road lights, heater, fans etc). You can connect your alt. sensor wire here too.
---I send power to the fuse box directly from a 250amp junction block off the battery (protected with 100amp circuit breaker).
---I run 30 amp rated toggles for added accessories but no relays...or you can run lower amp-rated switches with relays.
---The wipers, heater and horn you can run off the acc side of the ignition switch as long as the switch is amp-rated high enough to handle the draw of those and other stuff you have connected to it. HOWEVER, that's a lot of accessories to run through the ignition switch for my tastes.
---If your OK with being able to use any particular accessories in key-off, you can run them off your auxiliary circuit through your aux fuse box (which is connected to the the battery).

 

Indeed that blue wire could be causing a draw.

The Delco internally regulated alternator (10si, 12si) has three wires:
1. The charge cable/wire goes from the major stud to the battery, usually connected at a major junction block that's connected to the battery.
2. The sensor wire is connected at the fuse box. Its often just looped back to the charge terminal/stud, and this works but is not ideal.
3. The warning light wire is connected at the dash and is hot when the alternator is putting out juice. It is a ground when the engine isn't running (alt not spinning). The light is turned on by running a wire from the acc side of the ignition switch to the other pole of the idiot light. Once the engine fires and the alternator is putting out juice, the wlw is then hot, the light looses it's ground and it goes out.

If you've got the warning light wire connected at the ignition switch "bat" terminal, when engine is off it's putting out ground and causing a draw. Without a warning light, the wlw is usually not connected anywhere.

 

The small wire on your alternator plug( #1 or the blue wire ) is used to excite the windings of the alternator so that the alternator starts charging immediately. You can run the alternater with this wire unplugged but it will not start charging until you turn it above a certain rpm ( not sure what that is) , this is exactly how a one-wire alternator works.

 

Dear all, thanks for all the advice and suggestions so far. It seems this blue wire is generally what is causing most concern from all the advice I have received.
The alternator is a remy 20039 with 63amp output at the 3 o'clock postion.
remy 20039 alternator wiring' - Google Search
it's now clear that my blue wire is not correct as this is designed only as a charge light indicator, that being said I just disconnected it and found no change in the charging/discharging issue, even after revving the engine to activate a charge. Turning my light switch on while the engine is running drops my ammeter to 30 amps discharge. I am getting 14.4volts on the battery at idle though so i'm confident the alternator is putting out a charge.
This diagram was sent to me on the CJ3 forum...https://www.thecj2apage.com/forums/uploads/2682/wiring_diagram2.jpg
It show he right hand spade terminal of the alternator connected directly to the amp gauge whereas mine connects directly to the battery. This diagram also doesn't include the use of the left hand spade connector on the alternator or the main charge wire from the alternators positive terminal.. i assume this diagram shows what is described as a 'one-wire' alternator? Is there any harm in following this diagram with the addition of using the main positive cable to the battery as in my diagram?

Glenn.. the 20 amp fuse is an original piece and was wired in this way when I found the jeep. would you say that this is in the wrong place? also yes I believe all 3 wires from the alternator are hot in my diagram.

oldriginal86 and 66cjlasvegas.. it seems from these diagrams that the blue wire is a warning light wire? delco remy 10si alternator wiring diagram - Google Search:

sierra bum: what do yo mean exactly when you write "The light is turned on by running a wire from the acc side of the ignition switch to the other pole of the idiot light" from my understanding you are suggesting that I connect the blue wire from the alternator to the accessory side of the ignition switch and then on to a lamp in the speedo cluster (speedo cluster is grounded through the body)
??

Thanks again you guys, I feel like i'm getting closer to solving the riddle.

 

See my post regarding the 3 wire Delco alternator. I run a 140 amp 3 wire alternator in my jeep.

Also, check out the tech section on 3 wire alternator in MAD electric

A typical ignition switch has 2 "on" positions (or 3 if you include "start"). Ignition and ACC, or accessory. The "ignition" position activates both the ignition circuit and the acc circuit. The acc position does not activate the ignition circuit; say for example you sit in your car and listen to the radio...you park, turn off the engine and then switch the key to ACC.

You can connect whatever you want to the ACC pole on your switch. Its sending + power. But know that the switch has an amp load rating like any switch. Common accessories here are the stereo, wipers, heater blower or even power windows. Its possible to beef up the load capacity of this circuit with a continuous duty relay/solenoid.

So to the warning light wire...say for example you have a 1/4" red LED light for the charge warning light on your dash. That little light has two poles. One pole gets + (juice) and one gets - (ground) for the light to turn on. What I am suggesting is that the warning light wire from the alt goes to one pole on the light and you run a wire from the ACC pole on the ignition switch to the other pole on the LED warning light. When you turn the key "on" the light turns on...its getting + juice from the ignition switch and - ground from the alt wire. Then you turn the engine over, it fires, the alternator spins and sends out + juice through it's "warning light" wire, and now the light goes out because it looses its ground. The light works as a warning because if you're driving and it comes on, your alternator is not putting out current and that is communicated through that wire (broken belt, bad alt, alternator on fire, etc.)

So... to your problem. I think your parasitic draw could be either the ammeter, your charging setup or the ignition switch:
The problem with using the warning light in the original cluster, if there is one, (not sure how that is on the 3b) is that it's designed for the externally regulated alternator. Not sure how to adapt the newer alt to original cluster.

Thoughts: Is the ammeter wired backwards? Maybe Its really charging but you have the wires on the wrong poles of the ammeter. 14.4 volts would indicate the alt is putting out current. Make sure the two small ALT terminals are going to the right places...it would be easy to mix them up.

If your alternator is rated at 63 amps, theoretically it could fry your stock ammeter (or worse, cause fire) that maxes at what, 30 amps? (that's probably why the PO put in a fuse). Remember an ammeter is wired in-line (series) to whatever circuit it's measuring and it needs to be able to carry the full load of that circuit.

Question: looking at your diagram, it appears the headlight switch gets power through the ignition switch "ign" pole. Do you have to engage the ignition switch to use the headlights?

I still suggest a volt meter and an alt warning light. In my mind this gives better information on the electrical system, is safer and better suited to a more modern set-up. Unless you really want the original scheme. In my jeep i ditched the stock cj5 cluster and installed aftermarket gauges. So all the wiring is my my own crazy hair-brain invention.

 

This is all really helpful info Sierra Bum, i'm going to make some wiring changes based on all of the advice everyone has given me here.

So I went back to the blue wire and removed it and retested and it seems it was in fact the current draw culprit!! so stoked I have finally got rid of that problem! such a relief.

However, the ammeter is still not registering a charge. I too had wondered if it was wired the wrong way around but if this was the case then the dial wouldn't jump to -30amp discharge when I turn the light on. It seems that either the ammeter is broken (although i'm not convinced if it works to show a -30amp headlight discharge) or the alternator is not wired up to it properly?

Before I had connected the right spade terminal on the alternator to the battery terminal I was not registering 14.4v across the battery. i.e. it was only when i had connected this wire that the alternator seemed to begin charging. Do you think I can splice/rig up an additional wire from this spade to go directly to the ammeter? and if so would i have to change any of the other wiring? presumably the wire would need to handle 63amps maxed out if i did this?

Looking at my diagram (removing the blue wire altogether now) can you see any reason why the ammeter wouldn't show a charge given the existing wiring setup?

Answers to some of your questions....

Ammeter dial face shows it's max reading as 60amps (only reason why I want to keep this is because it's an original piece and i'm not certain yet if it is broken)

I don't think the ammeter is wired backwards as I described above

Yes I connected the flasher and headlights to the ignition switch which I will now move to the ACC terminal of the switch instead... although, either way, would this effect the charging circuit through the ammeter?

I checked the alt terminals, if I swap them around i loose charge on the battery and see no difference at the ammeter. Also these diagrams would suggest i have them the right way around remy 20039 wiring diagram - Google Search

Thanks again for any more clues and advice.

Finally got my windscreen back today which is the major last piece of my rebuild.

Final pics to follow soon!!

 

In all honesty, I've never liked ammeters in a dash. FWIW, I do not think that a 60 amp ammeter is original to a CJ3b. Originally that thing had a 30 or so ammeter because it probably came with a 35 amp externally regulated alternator or even a generator with the factory 4 banger. I'd be curious to know for sure.

My understanding is that a DC ammeter is properly wired in line (in series) with the charging circuit (or whatever circuit its metering); so in this case, between the alternator and the battery. Yours is between the starter and the ignition switch. So its not giving a direct reading. Before high amperage alternators, 35 amps could probably be handled with a 12 gauge wire. To put this in perspective I have a 140 amp alternator that runs a 4awg battery cable for the charge wire. There's no way I'm running that cable from the alternator, to the dash and then back to the battery just to get a amperage measurement, (and by the time I make that long wire run I'm up to a 2awg cable). So like most modern charging systems, I have a simple volt meter with a short 18awg wire that reads off the fuse box and a warning light. Otherwise for an ammeter the solution would be a separate wire run with a shunt that goes from the alt/battery out to the dash and back allowing for a smaller gauge wire. Lots of extra work and wires and doodads and to me not worth it just to have an ammeter that I'm not going to find anyway that reads 140 amps.

Read this biased thread on ammeter: HAMB

For your alt wires (I don't recall the terminal markings off hand), the remote sensor wire can be looped back to the charge terminal on the alt for simplicity, and the charge/output wire/cable can go to the battery. A breaker on this wire/cable can be used if you're paranoid (I'm paranoid). If your not using a charge warning light, that alt terminal/wire is defunct.

As far as the ignition switch is concerned, it probably has as rating of 25-30 amps or so. If you tie in your headlights, wipers, heater blower and stereo not to mention the ignition circuit, you're way too close to max amp capacity of that switch IMO. So my suggestion is to be careful how much load you put on that switch. Again I'm paranoid. There is a way to beef it up, but it means adding an extra circuit. So, know/learn the amp draw of your accessories and add them up for a particular circuit load.

Potential solution:
1. Ditch the ammeter and the wiring on both sides of it.
2*. Now make a wire run either from a busbar fed directly by the battery to the bat terminal on the headlight switch... or more simple... from the starter bat terminal to the headlight switch bat terminal.
3. Then run a wire from the Bat terminal on the headlight switch to the Bat terminal on the ignition switch.
4. Play it safe. Use at least 12awg wire for the above runs.
5. Wire in a volt meter to the ACC terminal on the ignition switch. There are better places to wire it in but for simplicity sake this is good. And a volt meter is safe.

*you gotta be OK with the headlight switch being off the ignition switch circuit for this to work. Fwiw this is how the ECJ5 is wired from the factory.

Last bit of diatribe: one major advantage to wiring certain accessories to the ACC side of the ignition switch is that you can power them (stereo for example) without running standing juice through your ignition circuit "engine off", which can burn up your points or your electronic ignition.

 

You may find this chart helpful if you don't already use one as wiring resource to calculate the correct wire size for the run length and circuit type:

 

The other reason using the accessory side of the switch is to separate those circuits. If the alternator power is connected on the ignition side of the switch the engine won’t shut off.