Author Topic: Alternator not charging/ starter switch ground  (Read 1560 times)

hotrod68ss

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Alternator not charging/ starter switch ground
« on: April 10, 2022, 11:35:35 PM »
So, Electrical is NOT my thing. My 68 camaro charging system has never worked since I got it. Changed the alternator, Voltage reg, horn relay, ignition key tumbler....no change. I went to Change the ignition switch itself, and found no wire going into the factory connector on the back of the switch for the ground blade. Car ran fine except it never charged the battery, every worked save the lighter and and it never charged the battery. Shouldn't there be a ground wire going to the ignition switch, and could this be my problem or just another one?
« Last Edit: April 11, 2022, 12:19:38 AM by hotrod68ss »

Kelley W King

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Re: Alternator not charging/ starter switch ground
« Reply #1 on: April 11, 2022, 12:25:35 PM »
I would say the charge wire on the alternator(usually red on the screw post) is broken between the alternator and the battery. Not on a 68 camaro but on one of my cars the wire was broken near the starter which is where it connected to the battery cable. A simple jumper from the post to the positive battery cable should show if that is your problem. If so then trace the wires.
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David K

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Re: Alternator not charging/ starter switch ground
« Reply #2 on: April 11, 2022, 10:34:29 PM »
We need specifics before we can help.
You didnít mention how old the battery is and if itís been tested. You canít properly diagnose a charge system issue with a partially charged or failing battery.
How do you know the regular system isnít working properly?
What is the reason you suspect this?
Does your car have gauges or a light?
Is the wire from the alternator to the battery in good condition?
We need Specific voltages for the following if we are to help. 
Actual battery voltage with the car not running.
Actual voltage with it at idle, 1,000 rpm, 1500 rpm at both the battery, alternator output, voltage regulator.
Are all the parts stock replacement or are there any non standard pieces?
Electrical may not be your thing, but stop throwing parts at it.

hotrod68ss

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Re: Alternator not charging/ starter switch ground
« Reply #3 on: April 11, 2022, 11:31:53 PM »
The battery is one year old, they replaced it before they shipped the car to me. probably due to this issue which I am sure existed before I bought the car. The voltage at battery is 12.6 before start the voltage at battery is 12.6 after start the voltage at 1500 is 12.6. The battery holds a charge a long time if not used. Car has a tictoc tach and gauges the generator light, as per factory, does not light up upon start or any time. the brake light does. Everything else electrical in the car seems to work, even courtesy lights. The ampmeter works but shows only 12 volts at any speed. Less if the lights are on which will kill the battery eventually. The car will run at least 100 miles on the battery during the day (I have not driven further). All parts were stock replacement except voltage reg which was solid state but made no difference. The original  voltage reg is back on the car. The parts are cheap, like dirt cheap, if I want to throw parts at a car, I can. It's my car, and it hasn't made a difference so i don't see your criticism. It's not your money. the last thing I want to do is chase wires, I hate it. I may have to do it, but if I can eliminate everything else beforehand cheap, then ok by me, and I'm the one that counts. It all points, stock coil, nothing aftermarket. It is stock. I'm curious at the ground from the factory connector at the starter switch that I mentioned, there is no wire going to the blade. Shouldn't there be? the battery does not lose much a charge even after a 60 mile run during the day (no lights or radio use), it's still well over 11 volts, it just never charges. Oh I know the voltage because I used a multimeter on the car, and I constantly do so to make sure I have an optimal charge before I take it out. So, I've check at the alternator, during start up, running, after a trip etc.





z28z11

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Re: Alternator not charging/ starter switch ground
« Reply #4 on: April 12, 2022, 02:14:56 AM »
Here's a couple of pics that might help from the Chassis Service Manual. I notice you didn't mention the junction block on the radiator support, which supplies voltage from the alternator back into the battery. Check the voltage at that point with the car running, might give you a clue as to what the battery is seeing in terms of voltage. Also check the voltage output at the back of the alternator, should be 14.25 volts at about 1700-2000 rpm. If not, I'd suspect another problem to be the alternator.

12.6 volts on the battery is fully charged (as you noted), anything below 12.2 is considered discharged (although you can still likely start the engine). Your ignition switch should have 7 wires on it, I susoect the 20 guage black wire (6 o'clock position on the switch here in the wiring diagram) is the one you are missing ? That shouldn't have an impact on the charging system in my estimation. I meant also to ask if the wiring at the voltage regulator has been re-assigned, or is the original harness intact ?

Don't laugh too much, but I recently discovered the prudence of carrying a battery jumper with me, due to a failed battery on my wife's Tahoe when we least expected or needed it. I borrowed an Imazing jumper from a kindly Samaritan in the parking lot, and cranked it right up. Battery showed 10.3 volts, new GM electronics won't start with that kind of voltage. I did, however, get a text from Onstar about 15 minutes later that my battery was low, and to start the vehicle immediately. Honest -

Regards,
Steve
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David K

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Re: Alternator not charging/ starter switch ground
« Reply #5 on: April 12, 2022, 05:13:40 AM »
Itís not criticism because you stated electrical is not your thing. Youíre asking for help, and me (and others) specifically Z28Z11 are trying to help. Learning how to properly fix your charging problem requires understanding why the problem is still there from the previous owner; who you suspected couldnít fix it, and youíve replaced part after part. Good luck.

rich69rs

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Re: Alternator not charging/ starter switch ground
« Reply #6 on: April 12, 2022, 08:07:29 PM »
Just out of curiosity, what type of voltage regulator do you have?  Original mechanical or a modern solid state model?

Years ago, I purchased a modern solid state voltage regulator.  I took the black cover off of the original and installed it in the solid state model to maintain the look of originality.

IMHO eliminating the original mechanical type did away with an inevitable failure point.

As mentioned earlier - with engine running, check voltage at the alternator.  If you have something greater than 14 volts at the alternator but only 12.2 or so volts at the battery I would suspect that the alternator is good but either the voltage regulator or associated wiring from the regulator to the battery is an issue.

Good luck

Richard
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KurtS

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Re: Alternator not charging/ starter switch ground
« Reply #7 on: April 13, 2022, 01:33:22 AM »
What's the voltage at the alternator? Between the alt output post and ground.
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rich69rs

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Re: Alternator not charging/ starter switch ground
« Reply #8 on: April 13, 2022, 05:09:11 AM »
What's the voltage at the alternator? Between the alt output post and ground.

In approximate terms, for a properly operating Ď69 Camaro charging system, engine running:

1)  Expect to have approximately 14-14.2 volts between the battery terminals.

2)  Expect an alternator output of approximately 14.6 to 15.2 volts. 

3)  Voltage regulator reads alternator output voltage at the main splice in the charging circuit and regulates that voltage to approximately 14.2 volts on the charging lead to the positive battery terminal.

I found the info at the following link along with the charging circuit diagram to be very helpful/informative.

http://www.madelectrical.com/electricaltech/chevymain1.shtml


Richard
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