Electrical power

ok i have finished the electrical rebuild i put a 200 amp alt on with a 4ga wire to the batt. everything is grounded good feeder wires but while the bronc is running all i have is 12.2 at best, all lights on 11.77. i had the alt down to advance auto and they tested it; it was pushing 16volts. i have just about lost my mind. it's a one wire alt system with a self exciting rotor. it has 2 other wire labeled: electric choke, and voltage indicator.

if anyone has seen this or know of the problem don't be shy. i want to drive her!

thanks!

Well I'd say either you have a bad battery with a dead cell or something is possibly causing a high resistance short. I'd use a multimeter, start thee engine and remove the battery connection and then see what the output is. If it is OK, then you have the culprit. If not You will need to start removing stuff from the load. You could do that be removing most of the fuses and if the problem goes away, then start adding one at a time while watching what is going on with the voltage.

Just one question, did they do a real load test on the alternator to see if the regulator is functioning properly?

Good luck,

>-

Here is an 83 diagram which is pretty accurate for 80 - 86. If you add the truck vitals to your signature it will help us be more specific.

well as it stands i believe they added a load not to sure. but i did think of something else tho. is it possible to spin the alt backwards and have it not work? but i did try unplugging the batt while it was running it stalled the second it got unplugged.

If your voltage indictor is not hooked up your Alternator will not work. I had a truck, in fact I think it was my Bronco, the dash bulb was burnt out, and the alternator wouldnt charge. Replaced the bulb and it worked fine

If its not hooked up, wire a light bulb to it, grounded and everything, see if it charges

escortwgn said:

well as it stands i believe they added a load not to sure. but i did think of something else tho. is it possible to spin the alt backwards and have it not work? but i did try unplugging the batt while it was running it stalled the second it got unplugged.

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As long as you installed the alternator in the same location and ran the belt the same it should not be spinning backward.

That confirms that your alternator is not putting out. Lets back up a bit, I'm going to attach some pictures, but what did you do with the old harness connections that were on the 1G alternator? The old harness had a green with red striped wire . Did you hook that to the new alternator plug ? If not, the alternator will not put out. Also, where did you hook the yellow with white striped wire that is on the new alternator plug? It must be at least be connected to the alternator output post, or where the voltage is distributed to the fuseable links, (the battery side of the start solenoid). Photograph the installation and the connections and post them .

Good luck,

>-

The first picture is the old installation, the second of the harness part that plugs into the alternator, the third is a diagram of the new alternator hookup in the system and the fourth is a modified version of the 1st, (that is the way my truck is hooked up as far as the fuse box is concerned, you are only concerned with the lower portion.

ok i tried doing the light buld on the indicator line, still nothing. but the second picture is the same as it is on my bronc. except for the white i have an optional hook up: electric choke. i do have an exciter circuit in the main wiring harness i could try plugging it in to the choke on the alt.

ALT.bmp

i hooked up the exciter line to the indicator wire of the alt and it works now. not sure what it does but i ran it for 15 mins placeing it under a load and in gear and it stays anywhere from 14.1 to 14.6 volts. i hope if someone else runs in to this they'll be able to use this.....

thanks for everybodies help!

escortwgn said:

i hooked up the exciter line to the indicator wire of the alt and it works now. not sure what it does but i ran it for 15 mins placeing it under a load and in gear and it stays anywhere from 14.1 to 14.6 volts. i hope if someone else runs in to this they'll be able to use this.....

thanks for everybodies help!

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That is because the line you hooked it to is the correct place for it to get a switched 12V from. If you want to improve the regulation a bit, move the yellow with white stripe wire to the main point that voltage is distributed from. It is the voltage sense line and surprising enough moving it from the output post on the alternator to where all the fuseable links attach, (probably the start solenoid in your case), will allow it to react faster to load changes.

Good luck,

>-

for the older bronco's 80 to 85 I believe, there is a voltage regulator on the fender between the battery and the solenoid, it should one of the three wires going to the alternator, check the connections on it, you might just want to find one out of an f150 or f100 from the same period. if its not eh alternator then it will be that

Krafty said:

for the older bronco's 80 to 85 I believe, there is a voltage regulator on the fender between the battery and the solenoid, it should one of the three wires going to the alternator, check the connections on it, you might just want to find one out of an f150 or f100 from the same period. if its not eh alternator then it will be that

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Not after you do a 3G upgrade.

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what in the **** is a 3 g upgrade? that's not even self explanatory

Krafty said:

what in the **** is a 3 g upgrade? that's not even self explanatory

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Sorry, sometimes I forget that now everyone will be familiar with all the acronyms.

The alternator on the 80 - 86 is known as a 1G, the 2G was the alternator series used on 87 - 92, and 3G became the premium alternator design to be used on Ford products for many years afterward. The 1G is basically the original alternator design and has an external regulator (mounted on the fender), the 2G has what is referred to as an internal regulator mounted on the back of the alternator with the external fan on the front like a 1G, the 3G design has an internal regulator plus the fan is located inside the frame instead of on the front and is referred to as a 1 wire system, (not sure why, because it has more than 1 wire, just that they don't run as far as they use to).

Escortwgn has upgraded his system to the 3G design.

Hope that helps,

>-

I didn't see it specified in the original post that this was a 3g upgrade, but it should be the same, since it's a one-wire hook-up. My 88 F-350 is similar, like the 2G. From what I've learned, any alternator needs to be "excited" to charge, meaning it needs an initial 12V kick to begin charging. And all the indicatior lamp does is tell you it's getting the power, if I understand the wiring diagrams correctly. Thanks for posting those diagrams, too, Seabronc. JSM84

Justshootme84 said:

I didn't see it specified in the original post that this was a 3g upgrade, but it should be the same, since it's a one-wire hook-up. My 88 F-350 is similar, like the 2G. From what I've learned, any alternator needs to be "excited" to charge, meaning it needs an initial 12V kick to begin charging. And all the indicatior lamp does is tell you it's getting the power, if I understand the wiring diagrams correctly. Thanks for posting those diagrams, too, Seabronc. JSM84

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Yah, something else I forgot to mention. The reason I knew it was a 3G is the size of alternator and the one wire bit. The indicator is optional, if it weren't there it would get the 12V from the same place.

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yes, I am also running a volt meter.

I just stick with a High output 1 g alternator and have no issues with wiring or anything like that. I like things simple. even if they don't seem that way.

I belive 3G is a type of wireless internet.... LOL only joking......