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Discussion Starter · #1 ·
I've got a thick Red, a thin blue, and a thinner white wire heading toward my alternator. They all go into an ugly wad of tape and all that emerge are the thick Red one with a broken off connector just hangin' in the wind, and the thin blue one (white stays inside). The blue wire is then butt spliced onto a white wire that goes into a 2 wire connector that plugs into the alternator. The 2nd wire on the connector is a short red one that is connected by a nut to the terminal on the back of the alternator.

My factory style wiring diagram shows the thick red wire SHOULD connect to the terminal on the back of the alternator and the junction block that my battery pigtail attaches to. And the blue and white wires SHOULD be on that plug in connector and the other end into the voltage regulator...real simple.

I don't know how long that red wires just been hangin' like that, but suddenly my battery's not getting charged. My first thought is to put a new connector on the thick red wire and screw it onto the alternator. But present wiring has me wondering if this is an internal regulated alternator and this was someone's way of bypassing the voltage regulator. Can I tell just by looking if it's internally or externally regulated?

If I went back to my wad of tape and continued the blue and white wires to the connector...which wire would go to which terminal in that plug in connector? Help?!?! Suggestions?!?! :confused:

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Discussion Starter · #2 ·
OK, so I charged up the battery, took it down to AutoZone to have the charging system checked, and the young man said the alternator's showing no output. I pointed out the hanging red wire and he said "I don't have no idea. Maybe the old guy can tell you what's wrong."

So I describe the situation to the "old guy" as we walk out to the E.C. and he says "I bet I know what they did!" (Somehow I KNEW he would) He acknowledged that there was NOTHING connected to the voltage regulator, and said that the alternator is the "generic" old chevy style that can be hooked up for EITHER internal or external regulator. He said that the previous owner had done a bypass with that 2 wire connector and effectively set it up in a "one wire" configuration.

He also touched the hanging red wire to the terminal on the back of the alternator and not only didn't we smoke the car...my amp guage (that had never worked) came to life and showed we were charging. So bottom line, he said clean up the wiring with some new ends and I should be good to go. I'll do that.

My question is, IF that red wire's been broken off since I owned the car (amp guage NEVER worked before) why have I NEVER had charging problems for the entire 10 months since I've owned the car? Also is that "one wire" bypass gonna give me problems down the road...or is it my current source of problems?

Again, any advice/insight is appreciated. :confused:

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For starters there's no such thing as a generic Delco alternator that was used as an externally regulated unit OR an internally regulated unit. It was one OR the the other. The cases were the same shape but the insides were not.
Take a look at the rear of the alternator in this link. One way to tell an external from an internal is by the connector pins. The internal SI alternator in this picture has the pins going (--). Is that what's on yours?
An external would have the pins going the other way (II).
http://www.madelectrical.com/electricaltech/delcoremy.shtml
 

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Discussion Starter · #4 ·
Thanks John that picture was helpful. And yes I thought they were specific...some sorts of diodes built into the internal right? I do have the (--) connection on my alternator. However there is NO connection at the voltage regulator...I can't even find any remnants of those wires or the connector at the VR.

This morning I took off that terminal nut on the back of the alternator, found the broken off piece of the Red wire's connector, put on a new connector and hooked it back up. I haven't taken it back down to AutoZone yet to have them check the charging system, but my amp meter seems to be just sitting at nuetral. If I turn on my headlights it drops into the negative. In my previous experience with unmolested wired cars, I would take that to mean my alternator isn't putting out and that I'm just running on battery. Easy enough to change out the alternator of course. But with that "jumper wire" going from the spade connector to the terminal, and the VR out of the loop altogether, I don't know if I'm getting some sort of false or inaccurate reading at my ammeter...I frankly, don't understand where the electrons are flowing or why it would be wired that way. Can you, or anyone, provide some insight?

In yet another direction...I understand that bypassing the voltage regulator isn't good for my whole system, what with the voltage fluctuating with RPM and all. What's involved in changing to a INTERNALLY REGULATED alternator? If I'm likely gonna be buying a new alternator anyway, and in that I'll have to do some wire surgery to put the external regulator back into the loop...might I be better off making the switch now. I bought a harness modified that way for my camaro and it works great. Maybe I'll ultimately do that for my E.C. as well, but in the meantime is making the changeover a good idea, and how would I go about it?

Thanks, :confused:

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Discussion Starter · #6 ·
Thanks so much. That's exactly how the wires look. So it sounds like I may just hava bad alternator at this point based on my ammeter sitting at neutral. I guess I'll go have it tested, go from there and stop worrying about it. Thanks again.

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Discussion Starter · #7 ·
Turns out the alternator tested good. I went in and traced/replaced some of the wires...got rid of 4 unnecessary butt splices (bit of a hack job this was) cleaned it all up and now everything works great...including my ammeter. Thanks Mr. Muha for the guidance.


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