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1965 charging system

1965ply

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I have a 65 belvedere wgn just finishing, started up not charging hooked the 2nd field wire to grd only charged 12.3v changed regulator & 3rd alternator and battery still only charges at idle 12.3 goes down to 12.1 when I pull the headlites on. the gauge on dash discharge with lites on until I rev up around 3 grand I have changed & added grd wires also what should the charging system be charging at??
 
You should be at 15 + V,how old is the battery ? Might be a good idea to have it load tested.
 
First I would check all connection & grounds.. Test Battery...Question is it a single field alternator ! wire????
From my manual testing alternator/regulator....
Battery test...
1. Connect the positive lead of the voltmeter to the positive terminal of the battery and the negative lead to the negative terminal.
NOTE: Protect your eyes with safety glasses or goggles when doing this procedure.
2. Remove the coil cable from the distributor cap.
3. Ground the coil cable to the engine block by connecting a jumper cable between the two. This will prevent dangerous arcing of the high-voltage spark.

NO-LOAD TEST
This test will determine whether or not the system is charging the battery and, if not, whether the alternator or regulator is at fault. It requires a voltmeter capable of measuring at least 16 volts, down to tenths of a volt.
If the charging system on your car has an externally mounted regulator, warm up the engine before performing the following test:
1. Turn off the engine, lights, and all other accessories.
2. Attach an engine tachometer according to the manufacturer’s instructions.
3. Connect the voltmeter to the battery by attaching the positive lead to the positive terminal and the negative lead to the negative terminal.
4. Note the voltmeter reading. If it is less than 12 volts, charge the battery. Then note the voltage reading again and record it.
5. Start the engine and slowly increase the speed to 1,500 rpm.
6. Note the voltmeter reading again. If it exceeds the engine-off voltage by more than 2 volts, the system has a faulty regulator, a poor regulator ground, or a short circuit in the wiring between the alternator and regulator.
7. If this voltage reading exceeds the engine-off voltage by less than 2 volts, perform a load test.
LOAD TEST
1. Keep the tachometer and voltmeter connected as they were for no-load test.
2. Note and record the voltage reading.
3. Start the engine and turn on the heater (or air conditioner) at high speed. Turn on all lights and accessories.
4. Increase the engine speed to 3,000 rpm and note the voltmeter reading.
5. If this reading exceeds the engine-off voltage by 1/2 volt or more, the charging system is functioning properly.
6. If his reading exceeds the engine-off voltage by less than 1/2 volt, perform a full-field test.

FULL-FIELD TEST
When the regulator’s control function is bypassed, the alternator runs full-field. The method of bypassing the regulator differs, depending on the type of vehicle. For this reason, Step 1 of the full-field test changes from car to car, while the remaining steps are the same for all models.
1C. Chrysler models. Turn of the engine. Locate the green wire connecting the alternator field terminal to the regulator; disconnect this wire from the alternator. Connect a jumper wire from the alternator field terminal to a good ground.
2. Once the regulator has been bypassed, repeat the load test.
3. If the full-field voltage exceeds the engine-off voltage by 1/2 volt or more, the regulator is defective and must be replaced...............do not jump the green wire to anything.
REGULATOR REPAIR
Once it has been determined that the problem is with the regulator and not the alternator, you can find out if the source is the regulator itself or its wiring or ground.
1. Check the wiring between the regulator and alternator for heat damage or wear. The regulator is usually mounted on the firewall or on the finder under the hood.
2. Remove the bolts from the voltage regulator.
3. Use sandpaper to clean off the area around the bolts and the spot where the voltage regulator mounts on the car. This will assure a good ground.
4. Clean, reinstall, and tighten the bolts.
5. Perform all of the troubleshooting procedures again to see if the problem still exists.
6. If so, the problem is either in the wiring or the regulator itself. If you have already inspected the wiring, try replacing the regulator
 
^^ Note that the above procedure depends on starting with a charged battery for vaild comparisons of proper voltage rise with the alternator. And, the full fiedd test is for the later Mopar alternator type, not the older one. So applhy thsi with some caveats.....

A charged battery will read 12.6 to 12.7 volts after 'resting' for an hour or more after a charge; 'resting' means no charger or load attached. The battery should see around 13.8 to 14.3 volts at fast idle when the alternator/regulator are working right. It will be a bit higher when cold.

To the OP, what regulator do you have? The older square style or the later model flat pack electronic regulator? This is important as the wiring to the alternator field is different between the 2 regulator types. Also, do you have 1 small terminal on the back of the alternator or 2? (This is in addition to the big output terminal.)
 
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