[taktikian]

Hello everyone, Having issue with charging issue. Two weeks ago car would not restart at Chinese restaurant. Would barely turn over. Luckily, there was an Advance Auto across the street and they installed a new battery. All seemed well. This Saturday wife and I took car to a paint and body shop for a lookover. Well he did not show up for our Saturday appointment and to add insult the vehicle barely turned over. Thought new battery was defective. AA kept battery over night and I went back Sunday morning and was told battery was good. One our later brought them new Powermaster alternator and that also tested good. Went and bought new voltage regulator still not showing any charging at battery but I know the alternator is producing because voltage at coil increases from idle with rpm's. GEN light now glowing red till about 1500 rpm's,never have seen that before but it happened after new regulator installed. Hoping for some insight here.. Tired of paying for incompetent mechanics, but the engine itself built by Gary H is running great

[25stevem]

What year is the car?
If you still have a cigarette lighter in place remove it for starters.

You must confirm with a voltmeter that once the motor is running with no lights or Heater blower on that you are getting 13 .5 volts back at the battery.

If your not then no battery is going to last .

If your red idiot light is then proven correct then I think your wiring harness may just be giving up the Ghost.

[taktikian]

I am showing 12.2 at positive alternator stud, same as battery. Running engine does not increase voltage at alternator. Thanks for responding

[taktikian]

Almost forgot, it is a 1970 with new external regulator,battery and alternator

[chuckies76ta]

12.2 Volts is not charging battery. Some reading on system. https://www.carparts.com/blog/a-shor...rging-systems/

Does your new power master alternator have the voltage regulator internal?

[Sirrotica]

It used to happen to me all the time before I retired from my job as a mechanic. Every bolt on part was new under the hood, and it still doesn't charge. All those new parts are connected together by wire and switches. Bolting parts on is fairly simple as opposed to hunting the real problem. Most likely there is a wiring problem, so bolting on every new part in the charging system doesn't fix it. Assuming that all the wiring is intact on a 50 year old car isn't troubleshooting the problem.

You need someone that knows how a charging system works, and knows how to use a VOM (Volt Ohm Meter) to chase the problem down. Diagnostic skills and analytic skills can find the problem. It get very expensive to keep replacing parts to try to diagnose a problem.

Any suggestions someone gives you on the internet, are again just guesses, you've already seen how unproductive guessing is when it comes to electrical problems. There are schematics to show you how the circuits are connected, and if you get a manual, there are troubleshooting trees to systematically eliminate possible problems.

Here is a basic troubleshooting guide from Haynes manuals online, it's not specific to your car, but it can point you in the right direction:

https://haynes.com/en-us/tips-tutori...ues-and-causes

[taktikian]

Originally Posted by chuckies76ta

12.2 Volts is not charging battery. Some reading on system. https://www.carparts.com/blog/a-shor...rging-systems/

Does your new power master alternator have the voltage regulator internal?

No, It has external regulator

[taktikian]

Thanks all for responses. Two problems, Number 1 is @ 71 years old bending over fenders or contortions under dash for any period of time is not doable and I do not mind paying for a job well done, I just cannot find competent people. Forum members are all long distance. And yes Sirroticca, swapping out parts is a lot easier than ripping open neatly packaged wiring and following diagrams which I have. Thanks again

[chuckies76ta]

Originally Posted by taktikian

No, It has external regulator

No disrespect meant here. I know your using an external regulator, I also know you said you have a new Alternator. I'm just wondering if the new Alternator has it's own built in regulator. Do you have a part number on the new Alternator?

[OG68]

From the 68 diagnostic manual.

[mgarblik]

Where are you located? There is probably a member here that can recommend a good shop in your general area. Charging systems on these old cars is pretty simple. Only 3 components involved and probably 6 wires or so. We are not talking about pulse width modulated voltage regulators integrated into the PCM, communicating in 3 computer languages to 17 other computer modules over 2 miles of wire all to charge the battery. The charge light on indicates a no charge condition, verified by you. Most likely an open in the field circuit. Any repair shop with an old gray hair mechanic should be able to find that within an hour. I hope so anyway. Let us know what you find.

[TedRamAirII]

Be sure the regulator base is grounded. Be sure you have a ground from the battery negative to the engine and the body. Use a volt meter and do a voltage drop test, that will find bad wires or bad connections. https://video.search.yahoo.com/searc...6&action=click

[taktikian]

I am in central florida. Another member mentioned possibly wrong alternator , will retrieve part #

[Half-Inch Stud]

Long ago the Solution to that problem was to clean& tighten or replace the battery cables.

Charging is evident with reading 14-14.4 Volts DC.
May have an alternator with a bad diode making AC happen.
May want to convert to an internal regulator alternator.

[taktikian]

Tonites plan is to re- install the Delco alternator which I replaced with new chrome Powermaster just to compliment looks of new engine. Thanks for responses, and links to informative articles. Will keep updating.

[chuckies76ta]

What’s part number of power master?

[taktikian]

Powermaster 17102. Decided not to re-install old Delco. Tried to do it right way by checking voltage at 3&4 at regulator. Leaning over fender and twisting to reach for regulator quickly reminded me why I do little of my own work nowadays. Car is going to CorvetteMasters hopefully next week. Thanks all for suggestions but I pretty much have to get to where the car is usable. Will let you all know what turns up

[chuckies76ta]

Ya that part # is suppose to be the 10DN which uses external regulator. Keep us posted. I would put a internal regulator alternator and bypass the external reg. or remove it altogether. I believe the 10si #17127 internal regulator.

[Schurkey]

I used to know this crap. Now I have to look it up, and I'm not having the success I'd prefer.

I won't own a car with a 10DN alternator; they all got the super-easy swap to a 10- or 12SI alternator, which involves a ten-dollar pigtail soldered and heat-shrink insulated; and two little jumper wires. Which means, I've not full-fielded a 10DN in about thirty years.

However, a 10DN alternator is easily full-fielded. Disconnect the 4-terminal (F, 2, 3, 4) wire harness connector at the voltage regulator. Start engine, run at fast idle. Probe Terminal 3 of the CONNECTOR, verify battery voltage. No voltage, repair wiring between battery and regulator connector. Then cram a jumper wire between Terminal 3 and Field on the CONNECTOR (not on the regulator.) If full-fielding at fast idle doesn't produce hum, and a heap of voltage and amperage from the alternator (Easily 14V+, and whatever the rated capacity for amperage is +/- 10%) then either the alternator is fried or the field wire in the harness connecting it to the regulator/battery has failed. If the alternator has output when full-fielded, the problem is in the regulator. If you don't have tremendous output, re-do the test at the alternator, between the output terminal and the Field terminal. If you now have output, it's the wire harness. If you still don't have output, it's the alternator.

https://alternatorparts.com/img/GM_e...tor_wiring.jpg

Of course you'd need to repair the wiring if that's the problem, but if the alternator itself has died, I think it's NUTS to put money into a 10DN alternator or the matching regulator. Swap to a 10- or 12SI alternator with internal regulator. Looks approximately the same, fits like it was made to go there. Dirt cheap to upgrade the field wiring to be compatible with the SI alternator. Better output at idle, generally more rated output. Better voltage regulation--fewer spikes.

Conversion schematic attached.

[Schurkey]

By comparison, full-fielding a 10- or 12SI alternator is as simple as running the engine at fast idle, and cramming the short end of an Allen wrench into the "D" shaped hole in the back of the alternator. Keep the Allen wrench in contact with the alternator case. Don't have to disconnect anything, stuff the Allen wrench or other metal probe into the hole (Not more than 3/4 inch deep) and ground the lil' tab on the internal regulator. Alternator hums and puts out a heap of voltage (~18 volts) and whatever amperage the thing is rated for.





Full-fielding of any alternator should be a time-limited process--the alternator will quickly overheat if you demand maximum output for more than a few seconds; and the rest of the vehicle will not appreciate the high voltage.