1800vw

6 volt or 12 volt Generators

Before Installing a New Voltage Regulator make the following test.

Do Not Remove Old Regulator until these Tests have been made. If the charging rate is low or if the generator is not charging at all, perform these tests.

#1 Check battery water and general battery condition. Check for specific gravity of 1.240 to 1.290 and make a load test with a cell tester.

#2 Check wiring for damage. Make sure all wiring connections at the generator, regulator and battery are tight and free from corrosion.

#3 Check generator belt for correct tension.

#4 Run motor at 1/4 throttle and check ground by touching one end of a heavy wire to the regulator base and the other end to a good ground or battery negative post. If the generator starts charging the generator is not properly grounded.

#5 If after checking the ground as described above in #4, the generator still does not charge, then with the motor running at medium speed make the following tests.
Note: An ammeter will be needed for the following test, not a tell-tale idiot light.

Step one is to momentarily touch a piece of #10 or larger copper wire between the D+ terminal and the B+ terminal.
Step two is to remove the DF wire from the regulator and momentarily touch it to a good ground. Note: this is only done briefly as this forces the generator to output maximum voltage

Note: If the generator was charging during step one or two, then the regulator is defective.
and if the Generator does not charge, the generator is defective.

Check the generator for worn or sticking brushes, weak brush springs, damaged commentator, open or shorted windings.

In step two, grounding the DF terminal Briefly run the generator at 1500 rpm (about 700 engine rpm), Generator output should show 14 volts. Then Briefly run the generator at 3000rpm (about 1300 engine rpm) Generator output should be about 36 volts. Some times you can hold the brushes tighter against the commutator (copper ring with slots the brushes normally sit against) with a stick or piece of plastic to clean off crud so brush contact improves. If the generator still supplies little or no voltage, the generator is the source of trouble.

If the generator is defective, then replace both the generator and the regulator.

If the charging rate is high and remains high as indicated by excessive use of battery water and burned out bulbs, then make the following test.
Check that the regulator base is well grounded to the car.
And with the motor running at a medium speed, disconnect the DF terminal from the regulator.
If the generator stops charging, then replace the regulator.
If the generator continues to charge, then the trouble is in the wiring and/or the generator.

Before Installing Generator or Regulator
#1 Disconnect the ground strap from the battery before removing Generator or Regulator.

#2 Before disconnecting any wires, Tag all wires to insure they will be replaced in correctly.
Note: If wires are connected to wrong terminals you can damage the regulator or burn out the Gen.

#3 Be sure a good ground is made between the regulator base and the mount. Scrape the mounting area before installing. On most applications there is a ground wire from the Generator to a positive ground.

A ground wire can be connected from Generator to the Regulator base with a sheet metal screw in the hole provided in Regulator base.

After Installing Generator or Regulator
#1 Reconnect the ground strap to the battery.

#2 Before starting the motor you should Polarize the generator as follows.
Momentary touch a jumper wire from D+ terminal to the B+ terminal.
Do not touch the DF terminal as the Regulator will be damaged.