Dead battery, Jeep quits, new alternator.

Lucihale

New member
Hey! Thanks for peaking. I just replaced my alternator because when tested, my system was pushing out one amp or so less than I need to run with headlights... This lead to me being all out of battery, and stranded with a stalled Jeep in the rain. Thus I was unhappy.
I put the new alternator in with some modifications to the mounts (alter. had one inch foot, mount had a two inch holder. Brass one inch spacer.) Plugged it all in, even disconnected my battery as to not void my warranty, and started her up. All seemed well...
Stopped at the store, it wouldn't start. I checked under the hood, and one of the wires leading to the new alternator was broken. Reattached, jumped and was on my way.
PROBLEM- Now it seems that regardless of the RPMs, or any other electrical draw, my battery wont charge and the Jeep will die if I try to drive anywhere. Turning on the headlights will make my engine stall in a matter of seconds, and my windshield wipers move SO.... SLOW....
I've heard my external voltage regulator may be to blame, but I don't really know much about it.

-'73 CJ5
 
Can't get there. Jeep dies. Unless I'm mistaken, (very possible) I should be able to run just fine with a dead battery, just wouldn't be able to start... I can't make it anywhere, it's like the alternator just isn't working at all, and I'm trying to run my jeep off of a dead battery.
 
whenever one changes the alternator they should ALWAYS change the voltage regulator too. They should have told you that at the auto parts store. you say the system was pushing one amp before, so that indicates the alternator wasn't dead and maybe the volage regulator wasn't energizing the feild properly. and also, the amps is not really a good way to test the system. a better way is with a volt meter. charge the battery and test the votage between the pos & neg battery terminals with the engine off. it should be 11 or 12 volts, they vary depending on the condition of the battery.next, start the engine and test the voltage again, now it should be 12.8-13.5 volts i believe. it needs to be higher that battery voltage, anyway.if it fails, and it sounds like it will, there is a test where you disconnect the voltage regulator and "full Field" the alternator. but it might be better for you to just take the alternator and the regulator to the auto parts store and get them tested. another thing is which wire broke off? because if you run the alternator with the big power wire(red i think) disconnected, that can easily fry the alternator and the auto parts people my get sticky about replacing it. good luck, john
 

Okay. I'm bad with wiring for the most part. I can repeat what I see, but I can't come up with answers very well. But here goes. There is a two pronged plug. Two wires lead into it. One of the wires comes FROM the plug and leads TO the post on the back of the alternator. A wire also leads AWAY from said post (I believe to the battery?) This is the one that was broken. Luckily, since someone else has rewired most of this CJ5 before, MOST wires are red. Grrrrr.
So I think I'm going to be the bigger man, and remove them and have the guys at the store test them like you said... Quick question though- is the white ceramic looking thing attached to my firewall my regulator? I have a feeling that it is, but I'm not sure.
 
From reading in other forums I'm starting to get the impression that I have an internal voltage regulator? My system looks very close to what they have described in this link... Alternator diagrams Does this change what I've got problems with?:???: Should I just bring my Alt. in? So confused. I HATE electrical problems. Hate them.:x

Also... Sorry, I've been reading non-stop and have been gathering more questions than most can handle... Speaking of which, John, I owe you a beer. If my ballast resistor (the ceramic thingy has a name!) isn't resisting enough, then the sensing in my alternator would cause it to put out a current that's too weak to charge the battery? Tell me if I'm talking crazy talk, I'm learning A LOT about alternators right now... I don't think I'm crazy...
 
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hi lucihale,
its john again. the ceramic thing on the firewall is called the ballast resistor, it drops the voltage at the ignition coil six volts and has nothing to do with the charging system. does your jeep have the stock engine? if so, it should be a ford type old fashioned alternator with an external regulator which is either a largish black box on the firewall 3"x5"x3"deep(mechanical) or a smaller silver box(solid state) at least i think its on the firewall but it might be on the fenderwell.
if, on the other hand, you have a chevy 350 engine which is quite common on old jeeps, you may very well have a modern delcotron alternator which uses sensing voltage and has an internal regulator and is what is shown on your link, but is not what you described on your previous post. the delcotron would have three wires: a big red one, and a connector with a medium and small wire.
if you go to cskauto on the internet you can see pictures of the various components. the delcotron would be on a 1983 jeep wagoneer, for example. also, electical systems are not that difficult, you just have to know the procedure. so hold on and don't look down, we'll get through this thing.
john
 

The alternator I just got and installed is a powermaster 8-46100. It's the stock 3.8L I6 232 engine. I don't see any boxes hanging out anywhere, but I'm going outside to look right now. I'm too out of a vehicle to not. I'll be back to you very shortly!
 
Okay! Here we go. From the model information I got, this IS a one wire alternator... Here's the setup-
 

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And I looked EVERYWHERE for a voltage regulator... Nada. That's bad right? Unless it's not a box... I have have no idea though.
 
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also check the fusible link on that red lead going to the battery circuit. it looks like a wire but it's function is similar to a fuse. this fusible link failure may mislead you to a costly replacement of an alternator as oppose to a 10.00 dollar part. it's just a possibility.
 
Thanks Mikey! I'm taking this thing to the parts shop to get it tested. There's something fishy going down. If there's no external voltage regulator, than I SHOULD have a resistor? Or some such thing to convince the alternator to put out more voltage? Hmmmm... One step closer though. You guys are great. I'll check the link tomorrow.
However, my question is still in play, I SHOULD be able to run on alternator alone once I'm started, correct? Even if my battery is dead. Or is charging the battery drawing enough to dull the whole system?
I get about 4 miles of driving with NO electrical accessories on in one jumpstart. He stalls when I push in the clutch and drop the rpms after about that distance. I also watched my headlights get dimmer and dimmer last night on my very scary drive home. So I have to be getting SOME current from my alter. right?
 

You are getting some very good info from these guys here. I had horrible alternator issues on my car a few years back. I went through 3-4 replacments. Come to find out, all of them had the internal voltage regulators go out and would suck the battery dry! My electical system was actually putting out way to much volts and was slightly pulsating my lights,interior and exterior. I went ahead and replaced again with a lifetime gurantee and so far (knock on wood) I haven't had a problem at all. I hope you can figure out what the deal is. I absolutely HATE electrical problems!!!
 
Thanks for the sympathy Jon! It's my primary vehicle too... Not too smart when it's 35 y/o, but hey, sometimes we can only afford to have toys that ARE tools. Sigh. It's a passion.
 

that's a delcotron allright with an internal regulator. the white wire needs to be hooked up to an alt light or a resistance wire, the wiring diagrams show a light bulb in parallel with a resistor. what i have done in the past is a dasshlight bulb and holder wired in series to the ignition switch "on" terminal. if you wire this directly to 12 volts, it will burn out the alternator. you must have a bulb or some kind of resistance in the circuit. this is what turns "on" the alternator. the red wire going from the no. 2 terminal(sensing voltage) directly to the main positive output (post) is unconventional but i think it should work. usually this wire is hooked up somewhere further from the alternator, such as the horn relay. good luck, john
 
Thanks a bunch John! On Friday I'm pulling the Alt. out to have it tested, as that could easily be the problem, and if all is well with the unit it's gonna be rewiring time. In which case I'll be reporting back here to make sure I'm doing it right. You've given me some pretty damn good instructions though, and I think I can do it right.
To be clear though (for me, I'm sure that's clear to most...) I need a 10 ohm resistor on the field wire BEFORE the ignition switch. AND a light running parallel to the 10 ohm resistor ALSO leading to the ignition? Should the light be lit at anytime or is it a warning thing?
Thanks again! I'll tell you how the testing goes.

Keep in mind that the way this is hooked up, is exactly the way my last alternator was hooked up, and it worked-ish, (Miraculously) all I did was put on new connectors. It seemed to be plug and go, I wouldn't attempt to rewire an alternator without coming here first. HAHAHA :D
 
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it should work like a regular old generator or "idiot"light, pardon the expression, if you wire it up with the resistor and light in parallel like the wiring diagram shows. on when the key is on motor off, and goes out when the motor starts. when i've hooked it up with just the bulb before, the bulb stayed lit all the time but got dimmer when the motor started depending on how big the light bulb was. the delcotron is a real depenable alt, best one in the world imho, should work fine. john
 
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