gen light came on - Team Camaro Tech
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post #1 of 7 (permalink) Old Jul 11th, 00, 12:21 PM Thread Starter
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My fellow enthusiasts have come to my aid before, and I once again seek your great advice.

I have a '69 Camaro w/BB 396. I had it in the garage for a few months rebuilding the heater core and controls, installing new coil springs, installing new stereo, and other maintenance / upgrades to interior, etc.

Got it running last week. Everything working OK. But, on the way home from a ride last Saturday night, the "GEN" light suddenly came on. I have a Voltmeter installed... it was normally reading in the neighborhood of 14 volts... and it suddenly started to read about <12 volts at the same time the "GEN" idiot light came on. So, I assume the "GEN" light is actually telling me something is wrong with the alternator or voltage regulator... as witnessed by the lower voltmeter reading.

A quick look under the hood showed that the belt was OK and the pulley was turning. Also, all the wires look OK... nothing shorted, broke off, fell off, or got caught in anything.

The alternator in the car is a 37 amp unit. I've owned the car about a year with no problems in this area. The alternator looks like a newer unit (bright, shiny outer case, looks clean and new), and the voltage regulator looks like new. Don't know how old either actually is.

Question: Where should I start looking for a problem? What could have suddenly gone wrong? Should I take the alternator off and take is to a auto shop for a bench test? What can I test myself with a VOM and basic tools? What usually goes wrong with these systems?

Also, if I need a new alternator, could I upgrade to a 42 amp or bigger amp unit without any trouble? What are the pros and cons of upgrading to more amps? P.S. - Next winter I am contemplating putting in a Vintage Air A/C - heater system... I assume this might require more amps.

Thanks in advance for anything anyone can offer as experience or advice.

Jim & his '69 Camaro

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post #2 of 7 (permalink) Old Jul 13th, 00, 05:37 PM
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I think that you are on the right track with having the alternator checked on a bench. Not much work involved to get it out. If you have access to a voltmeter, you can take a direct reading on the alt output, but I'd bet it will verify what your dash gauge is indicating. If you change the alt, its probably a good idea to cheange the voltage regulator at the same time. Cheap insurance. OR...
If the alternator is bad, you can change to an internally regulated alternator, (if originality is not a big deal). For more on that go to : Team Camaros' Tech Reference Page. good luck

Rick Schaefer
72 El Camino
TPI 350/700r4
68 Camaro
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post #3 of 7 (permalink) Old Jul 14th, 00, 10:13 AM
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I had a simialr problem with my 67. I ended up replacing the external voltage regulator. I'd almost bet that's what it is especially if alt tests okay. Good luck!
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post #4 of 7 (permalink) Old Jul 14th, 00, 10:18 AM
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Could it have something to do with the new stereo? Is is just a basic system, or did you install AMPS, crossover, EQ, anything else that could be drawing voltage? Maybe you alternator was just putting out enough to run everything, and that stero put it over the edge. I think you're on the right track, as far as going to the higher AMP alternator, I bet that would fix your problem. Good luck! KZ

[This message has been edited by kz1000ltd (edited 07-14-2000).]
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post #5 of 7 (permalink) Old Jul 14th, 00, 10:46 AM Thread Starter
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Thanks to Rick (Tech Team) and no1dc1983 and kz1000ltd for the replies and great insight based on your knowledge and experience:

Since initially posting my problem, I have since removed the cover from my voltage regulator (VR)and found that it has 2 sets of coils inside (as you guys probably know).

One coil has what appears to be a double set of points... I believe this must be the regulator coil and points. (The other coil is the field coil with 1 set of points, I believe.)

Anyway, the coil with the double points had an apparent fault... the lower set of points had a deposit from arcing, like a stalactite,or an icicle-shaped protrusion, sticking up from the surface of the points and permanently contacting the contact finger. I recognized this as the same kind of metal formation that occurs with a set of points from repeated arcing.

So, I filed off the "icicle" from the points surface. I started the car and noticed immediately that the "GEN" light no longer came on... ah... problem solved.

However, the Voltage gauge soon started acting up again, fluctuating from around 12 volts to 14 volts, the lights on the dash were flickering, and the voltage soon started climbing and pegged at 16+ volts... the max reading on my AutoGage gauge.

I wathced the VR while the car was running and noticed that the double set of points was opening and closing at a fairly rapid rate... probably like it should. There was slight arcing occuring each time the points opened and closed... as should be expected when making and breaking electrical contact. This would, of course, explain why the metal deposits occured in the first place to a point where the points were effectively always closed.

Anyway, now I am trying to figure out why the voltage gauge fluctuates, and why the lights flicker, and why the gauge pegs at 16+ volts.

I suspect, like no1dc1983 suggests, that in my case I have a faulty or out-of-calibration external VR. (I ordered a new replacement Delc0-Remy unit today from one of the faithful 1st gen Camaro parts suppliers.)

Regarding the idea that maybe my 37 amp alt is not big enough to power my radio upgrade, I'm pretty sure I'm OK in this category. I don't have a/c and the stereo I installed, a Custom Autosound unit, is driving 4 speakers, 2 under the dash and 2 under the rear package tray, but I'm not driving an amplifier or a CD changer (yet)... P.S. - the Custom Autosound unit is CD ready and has pre-amp outputs... so I can install more stuff someday... and may need more alt.

But 37 amps is good for "go fast" because it takes the least amount of horsey power from my mot.

I would,however, like to change over to an internally regulated alt someday because of the increased reliabilty and performance... but for now, I'm going to try a new external VR unit.

Thanks again for the help and advice... please let me know if you think of anything else... I really want to drive my car!

I'll let you know if I resolve the problem and what the problem was for anyone else who may benefit from my experience.

P.S. - I will go to the tech site that Rick noted to find out about int. reg. alts. Thanks.

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post #6 of 7 (permalink) Old Jul 14th, 00, 11:14 AM
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I'll add one thing to your last post. From what I've been told, a higher output alternator doesn't cost any power. It will only put out what the system needs or is using. A 100 amp alternator on your car would be putting out the same amount of amps and resultant power loss as your 37 amp unit. It just has the ability to put out more if needed than a stock unit.

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post #7 of 7 (permalink) Old Jul 21st, 00, 09:26 AM Thread Starter
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Hey everybody who helped me with this problem:

I fixed the problem. It was a totally bad external voltage regulator (VR). I bought a new VR from one of the excellent 1st gen Camaro parts catalog suppliers and installed it last night. It completely solved my problems. I now have a totally steady Voltmeter reading of 14+ volts when the engine is running, there is not fluctuations in voltage readings, the lights are not flickering or doing anything weird, everything works electrically... just like it did before the problem suddenly appeared on the way home from a cruise night.

I may have mentioned this before, but when I took the cover off the old VR to carefully inspect it, I found one of the fine gauge, insulated wires going from the frame of the VR to one of the coils had gotten old or "cooked"... it was in bad shape. So, at that point, I strongly suspected the VR was bad. It was.

P.S. - When I shopped for a new VR, I checked 3 different catalog parts suppliers... the prices were tops at $74.95, next at $49.95, and lowest at about $30.00. The $30.00 unit was a Delco Remy replacement, so I bought it. It looks just like the unit that was on the car, except my new unit has "Delco Remy" stamped into the cover. It seems to work fine.

So, what's with the difference in prices? Maybe it just pays to shop around, although I usually see prices much closer from catalog to catalog.

Anyway, thanks everyone, and there's my feedback on what solved my electrical problems in my "69 Camaro BB.

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