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Discussion Starter · #1 ·
Hello, I have a 67 Chevelle with an externally rated alternator. I have the solid state voltage regulator. I have ran this setup for about 3 or 4 years. These past couple of days I’ve been experiencing intermittent charging. I would be driving or idling and the voltage will go from 12 to 14 and I thought my voltage gauge was incorrect but the I checked the voltage at the battery and it’s fluctuating. All my connections appear clean and tight and I’ve never experienced an issue like this before. I’m assuming my alternator is dying on me but I’m not sure and I don’t want to waste going out and buying one if I don’t need it. Is there any way I can pinpoint the problem whether it be in the wiring, the voltage regulator, or the alternator? Any help is greatly appreciated, thanks.
 

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What do you mean by intermittent? At idle you have 12 volts and at higher RPMs you have 14? This could be normal.

Are you running any high draw electrical items?

Make sure your alternator and regulator are properly grounded through clean steel.

Hook up a voltmeter to your battery and shake and move the alt and regulator wires while the car is running. You're looking for that voltage drop.

The problem with intermittent is all will test good until the failure pops up. At that failure point, I would do a full field test on the alt, and if I saw about 16 volts would suspect the regulator.

To do a full field test on the alt, hook up your volt meter to the charge output of the alt, then use a jumper wire between the alt out put and the field lead, #1 on the alt plug. You should see an immediate jump in voltage to about 16 volts. What this does is takes the regulator out of the loop and tell the alt to output full power. If the alt doesn't put out 16 volts it's the alt. If it does put out 16 volts it's the regulator or wiring to the regulator.
 

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Discussion Starter · #3 ·
What do you mean by intermittent? At idle you have 12 volts and at higher RPMs you have 14? This could be normal.

Are you running any high draw electrical items?

Make sure your alternator and regulator are properly grounded through clean steel.

Hook up a voltmeter to your battery and shake and move the alt and regulator wires while the car is running. You're looking for that voltage drop.

The problem with intermittent is all will test good until the failure pops up. At that failure point, I would do a full field test on the alt, and if I saw about 16 volts would suspect the regulator.

To do a full field test on the alt, hook up your volt meter to the charge output of the alt, then use a jumper wire between the alt out put and the field lead, #1 on the alt plug. You should see an immediate jump in voltage to about 16 volts. What this does is takes the regulator out of the loop and tell the alt to output full power. If the alt doesn't put out 16 volts it's the alt. If it does put out 16 volts it's the regulator or wiring to the regulator.
I’m not running any high draw electrical items. The intermittent drop can occur while idling or driving. I can be driving down highway and look at my volt gauge and the car won’t be charging and then a minute later it will be charging again. I got home and put my voltmeter on the battery and the volts will be fluctuating from 12’s to 14’s. I’ll do the tests when I get in the garage later and report the results. Just to make sure, I’m performing the full field test on the alternator while it’s running correct? Can I put the jumper wire on and then start the car or do I have to install the jumper wire while it’s running? Thanks.
 

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Yes the car will be running and no you don't want to leave it on there you just want to start the car check your voltage and then tap the wire to that number one plug .

It won't really be a valid test unless the low-voltage condition is present. That's kind of the problem with trying to figure out what's going on with the intermittent issue.

Make sure you do the wire Shake test over there by the regulator and on the wire loom run into the alternator and at the plug at the alternator and see if your voltage drops
 

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Discussion Starter · #5 ·
Yes the car will be running and no you don't want to leave it on there you just want to start the car check your voltage and then tap the wire to that number one plug .

It won't really be a valid test unless the low-voltage condition is present. That's kind of the problem with trying to figure out what's going on with the intermittent issue.

Make sure you do the wire Shake test over there by the regulator and on the wire loom run into the alternator and at the plug at the alternator and see if your voltage drops
Ok, I did the shake test and I shook the battery cable and on one of the wires was crimped on more of the insulation than the wire itself. The volts were fluctuating when I shook the wire and after I loosened the connector and moved the wire back some it fixed everything. Thanks.
 

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Ok, I did the shake test and I shook the battery cable and on one of the wires was crimped on more of the insulation than the wire itself. The volts were fluctuating when I shook the wire and after I loosened the connector and moved the wire back some it fixed everything. Thanks.
What kind of terminals do you have ?. Were they like below that takes a stripped end of a wire then clamps onto it ?:



Jim
 

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You should get yourself a good Wen soldering gun, get the dual heat gun. Solder every electrical connection you make. I've removed most of the plugs on my harness and soldered the connections. While the soldered connection is still hot wrap it in heavy friction tape. Make sure you always use scissors when cutting the tape. Ripping it off the roll damages the tape and it will start to unwind. Its like always using wire strippers set for the correct gauge wire it so important.
 

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Yes, I have that on the positive and a different one on the ground because I have a quick disconnect.
I'm not trying to harp on anyone but think about at least getting a crimp on ring terminal for the end of the wire(s) and then buy the terminals with the wing nut on it. Once you get a clean stripped end of the wire, crimp it on, then solder it if you want and you should have a longer lasting connection. I wasted a lot of time a few weeks back when a guy had those terminals buried under electrical tape and turned out the bolts were loose and the wire end was corroded. Once it got cleaned up and tight he was good again but he knows and will do a better connection next time.

If you don't have a good crimper, take a trip to the local car stereo place and maybe they can make a better connection for you and not cost a whole whole lot.

Jim
 

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Discussion Starter · #10 ·
I'm not trying to harp on anyone but think about at least getting a crimp on ring terminal for the end of the wire(s) and then buy the terminals with the wing nut on it. Once you get a clean stripped end of the wire, crimp it on, then solder it if you want and you should have a longer lasting connection. I wasted a lot of time a few weeks back when a guy had those terminals buried under electrical tape and turned out the bolts were loose and the wire end was corroded. Once it got cleaned up and tight he was good again but he knows and will do a better connection next time.

If you don't have a good crimper, take a trip to the local car stereo place and maybe they can make a better connection for you and not cost a whole whole lot.

Jim
Will do, thanks for the tip.
 

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Discussion Starter · #11 ·
Well, I was driving yesterday and the problem presented itself yet again but it seems as though it is getting worse. I went on a drive for about two hours total and I’m watching my volt gauge the entire time. About 10 minutes in I notice it’s not charging again. I should’ve had some wire with me but I didn’t do I kept going to see if it’ll start charging again and eventually it did about 30 minutes later. Now I thought if I wasn’t charging then the battery would die after so many miles but I proceeded on and even had all my lights on and the bolts never went below 12 which is weird to me. Of course I went to do the field test on the alternator today and it’s charging ! I shook some more wires but nothing changed so I tried the field test anyway with it charging and the volts never went up to 16. What’s the deal? Maybe I’ll have to keep driving and when it stops charging I’ll have some jumper wire with me and do the test but other than that I’m not sure.
 

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Discussion Starter · #14 ·
I'd take a multimeter with you and test somewhere like the lighter. You need to separate if it's the alternator or the gauge.

If the gauge says no, but the meter says yes...
Definitely not the gauge, I tested at other locations and the results were the same. At night the lights were dim inside the car and when it would start charging again I could see the difference immediately. Thanks for that suggestion.
 

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Intermittent problems are fun to find.

I would start out when it does happen making sure you have the proper voltage on the external regulator to where maybe you are loosing voltage due to something like a bulkhead connection issue and when the voltage is gone, the alternator turns off but then vibrations has the connection returning ?.

While I do not remember the exact issues I had on an internally regulated alternator, both the internal and externally regulated models have windings of wire in the case and the wire used is what they call bell wire that is a solid copper center but then is coated with a lacquer coating that acts as the insulation. On mine the wire ends had terminals crimped onto them and from what I could tell it was not a solid connection to the core copper wire. I ended up removing the crimp connectors, sanding the wires coating off better than what it was, crimping on a new terminal, and then soldering it all together. Never had an issue after that with that alternator.

Also too if you are to have a particular voltage at a terminal on the back of the alternator, the voltage should be the same at the other end where it plugs into the external regulator (or at least real close to the same).

Jim
 

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When you did your last field test, did the voltage increase above battery voltage?

Make sure the wire you are using in the field test shows battery voltage before the test.

You've got conflicting results. Either your wiring is bad or regulator is bad per the good 16 volt output or your alternator is not outputting voltage per the negative test.

Does your gen light on the dash come on with the key on and the engine off??
 

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Discussion Starter · #17 · (Edited)
When you did your last field test, did the voltage increase above battery voltage?

Make sure the wire you are using in the field test shows battery voltage before the test.

You've got conflicting results. Either your wiring is bad or regulator is bad per the good 16 volt output or your alternator is not outputting voltage per the negative test.

Does your gen light on the dash come on with the key on and the engine off??
The voltage did not increase above what the battery was already charging at which was 14-14.5 volts. The wire does show battery voltage. The gen light does come on with the key in and the engine off but it does not come on when the system isn’t charging. Since my alternator did not output the 16 volts after jumping the F terminal to the output terminal does that make my alternator bad? The alternator was charging when I performed the test at around 14-14.5 volts.
 

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Discussion Starter · #18 ·
Intermittent problems are fun to find.

I would start out when it does happen making sure you have the proper voltage on the external regulator to where maybe you are loosing voltage due to something like a bulkhead connection issue and when the voltage is gone, the alternator turns off but then vibrations has the connection returning ?.

While I do not remember the exact issues I had on an internally regulated alternator, both the internal and externally regulated models have windings of wire in the case and the wire used is what they call bell wire that is a solid copper center but then is coated with a lacquer coating that acts as the insulation. On mine the wire ends had terminals crimped onto them and from what I could tell it was not a solid connection to the core copper wire. I ended up removing the crimp connectors, sanding the wires coating off better than what it was, crimping on a new terminal, and then soldering it all together. Never had an issue after that with that alternator.

Also too if you are to have a particular voltage at a terminal on the back of the alternator, the voltage should be the same at the other end where it plugs into the external regulator (or at least real close to the same).

Jim
The voltage at the back of the alternator is the same at the horn relay, the connection block on the firewall, the battery, and the bulkhead connector. I haven’t checked the voltage at the regulator when it’s not charging but if it does it again then I’ll be sure to check.
 

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The voltage at the back of the alternator is the same at the horn relay, the connection block on the firewall, the battery, and the bulkhead connector. I haven’t checked the voltage at the regulator when it’s not charging but if it does it again then I’ll be sure to check.
You should have 4 connections on your external voltage regulator with 2 of the 4 going to the back 2 wire plug on the alternator, a single terminal on the regulator that will show power all of the time which in the loom branches offto the horn relay buss, the alternator output stud and the junction stud by the battery, and then the fourth which is off of the GEN light and ignition switch. If the GEN light portion is not working or sending the proper signal to the voltage regulaor, then the alternator will think the engine is off and the alternator will be off.

Jim
 
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