Battery Drain
12-30-2006, 02:17 PM
#1
Melting Slicks
Thread Starter
Battery Drain
My '65 drains the battery only when the light are on at night. The lights are also very dim. No problems with daytime driving. Where should I start the trouble shooting? Alternator...Etc. Thanks
12-30-2006, 03:41 PM
#3
Le Mans Master
First off don't turn on your lights and second don't drive at night. Just kidding. I agree it sound like a voltage regulator problum.
12-30-2006, 08:08 PM
#5
Melting Slicks
Thread Starter
Jim, Did the regulator bypass and got 13.5 v at idle and up to 16v on raising rpm's, Alternator looks good. Regulator looks new (just bought car). Could it be something else or is there a way to test the regulator? Thanks Larry
12-30-2006, 08:12 PM
#6
Melting Slicks
Thread Starter
Jim, Did the test and Alternator looks good. 13.5 idle and 15.5 with higher rpm.s. Regulator looks new (just bought car). Can it be something else or is there a way to test the regulator? Thanks Larry
12-30-2006, 09:29 PM
#7
Melting Slicks
Thread Starter
Buns, Did the reccomended test and alternator look good at 13.5 idle and 15.5 - 16 at higher rpm's. I just bought the car and regulator looks new. Can I test the regulator or any other reccomended tests before I replace the regulator? Thanks Larry
12-31-2006, 05:57 PM
#8
Unfortunately, most of the tests for the regulator involve specialty equipment, such as
ammeters that can handle the full output of the alternator. There is one simple test that you can do.
REGULATOR VOLTAGE TEST
1: Connect a voltmeter from the junction block on the horn relay to ground at regulator base.
2: Turn on high beam headlights and heater blower motor to high speed. Run engine at or above
1500 RPM (for a few minutes, if necessary) and read the voltage on meter.
Note: Voltage will not greatly exceed 12.5 volts until the battery develops a surface charge, a few
minutes generally, unless the battery is severely discharged, or is hot. Shut off engine.
3: If the reading is less than 12.5 volts you can try adjusting the regulator voltage. Disconnect the 4
terminal plug from the regulator, remove the cover, reconnect the plug. You do this to insure you don't
short out the regulator. Repeat step 2 and turn the voltage adjusting screw to raise setting to 12.5 volts.
IMPORTANT: Wrap the shaft of the screwdriver with electrical tape as you do not want to short out the
regulator. Also, make final adjustment by increasing spring tension to assure contact between screw head
and spring support,
4: Shut off engine, remove plug from regulator, replace cover, reconnect plug. Cycle the regulator by unplugging
the connector from the alternator. Reinstall the connector and recheck voltage setting of regulator.
ammeters that can handle the full output of the alternator. There is one simple test that you can do.
REGULATOR VOLTAGE TEST
1: Connect a voltmeter from the junction block on the horn relay to ground at regulator base.
2: Turn on high beam headlights and heater blower motor to high speed. Run engine at or above
1500 RPM (for a few minutes, if necessary) and read the voltage on meter.
Note: Voltage will not greatly exceed 12.5 volts until the battery develops a surface charge, a few
minutes generally, unless the battery is severely discharged, or is hot. Shut off engine.
3: If the reading is less than 12.5 volts you can try adjusting the regulator voltage. Disconnect the 4
terminal plug from the regulator, remove the cover, reconnect the plug. You do this to insure you don't
short out the regulator. Repeat step 2 and turn the voltage adjusting screw to raise setting to 12.5 volts.
IMPORTANT: Wrap the shaft of the screwdriver with electrical tape as you do not want to short out the
regulator. Also, make final adjustment by increasing spring tension to assure contact between screw head
and spring support,
4: Shut off engine, remove plug from regulator, replace cover, reconnect plug. Cycle the regulator by unplugging
the connector from the alternator. Reinstall the connector and recheck voltage setting of regulator.