i was checkin the out put of the alternator, at the battery, and i am getting 11.59 volts at idle

it has a new(rebuilt) 65 amp alternator, and a new voltage regulator
the battery is a yellow top

is this the normal voltage?

thanks

 

does the voltage go up when you raise the RPMs? an alternator should put out about 14.5 +/- volts.
Bill

 

it does slightly, but not 14volts

 

AT 11.59v you are below static battery voltage. A fully charge battery will read 12.66v.
It seems to me that your charging system needs to be checked.
One quick way is remove the plug from the regulator.
Bring the RPM up to approx. 1200 and jump the red wire to the blue wire on the connector for a moment. The voltage should rise above 15v. If it does not rise at all then I would suspect an alternator. If it does rise I would say either regulator or a wire problem.

 

well i tried another good regulator and it was the same 11.59

so i guess i got a bad alternator; all the engine wiring was replaced

will an optima battery only command the amount of voltage it needs to charge?

the alternator it had on before was a newer style gm alternator but the only harness that was hooked up was the red wire only?

 

Got the ground (black) wire conected from the alt case to reg case?

 

yep all new wires all connected

 

 

 

ok i will give it a try!

BTW

what alternators is everyone running? i see the kits to run a newer style gm and the harness adapter is made to fit your wiring? is this worth doing? the alternator i installed is a 63 amp, but now i need to get another one by the readings, its only about 2 months old

thanks

 

Are you positive the "good" regulator was good? I was having a problem with my Amp gauge on my 65. I replaced the regulator with a new one and my Amp gauge stabilized, but I found I was getting about 11.5 volts at the battery. Seems the new regulator was bad. A second, new regulator solved the problem.

Jeff

 

when i bought the car this was the regulator that came with it, it also had a newer style alt with just the red wire hooked up. over the winter i replaced the engine harness assy, a new regulator, from zip products, and a rebuilt correct alternator. i believe when i tested it when i got it done it was putting 12+ volts

today i just tested it and it was puting out 11.59 when at idle, no change with acceleration, but when i put on the headlights, it was at 11.2

i just assumed the regulator was good, i never checked it before i took off the incorrect alternator, i dont know how it was charging with just 1 red wire?

 

Sounds like a "hot-rod" 1-wire alternator setup; you might want to read about 1-wire setups at www.madelectrical.com.

 

ok so i went to p-boys and had my alternator checked, passed all 3 test they did putting out 13v

so i bought another voltage regulator

installed that same reading 11.59volts

checked my battery with out the car running, 11.59 volts

does an optima battery not need a full 12volts? very strange, the starter does not lag cranks right over!!!

 

Your charging system is still not working. You must always have an overshoot of voltage in order to charge a battery. As stated previously, 14 volts is typical charging voltage. Since you are only seeing essentially battery level voltage, the alternator is doing nothing, and you are running on the battery (which will not last for very long - depending on load).

Your wiring is the next place to check. Follow Buns alternator test method as he posted previously.

Plasticman

 

Make sure the voltage regulator is grounded properly. There is a black wire from the regulator to the horn relay which is grounded to the radiator support. I would take a jumper wire from the battery negative terminal and run it to the case of the regulator.

If nothing changes then I would suspect that there is something wrong with your new wiring harness. This wouldn't be the first time.

 

ok i did this test and at idle i was at 15 volts

i ran a ground wire from the battery to the voltage regulator, still the same 11.65 volts

what next should i try??????

thanks

 

ok i might of found it!!

when i replaced my harness, i had to buy the alternator relocation harness, i found the black wire connector was unplugged
i reconnected and tried it, i still had the same amount of charge, 11.59
the battery is also at 11.59, so i hooked up a trickle charge to get it up to 12v and see what happens

 

when the engine is running, the alternator out should be in the neighborhood od 14.5 volts... even if it's 12, something is wrong...
Bill

 

Well, I do recall you said you were on your third regulator, so I doubt very much this is your problem. I'm assuming you are checking voltage at the battery, so I have to believe there is a problem in the circuit between the regulator and the battery. The only thing I can think of is the connection of the red power wire on the regulator to the starter solenoid.

But, what the heck, if you want to rule out the regulator as the problem, below is a test for that.


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.

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.