uwish

When my 81 is running (it runs smooth) the battery gauge is over charging . How do I fix this . Thanks

AT-82Collectors

I had the same happen on my 82, the voltage regulator in the alternator was bad. Replaced the alternator with a heavy duty from NAPA and it solved the problem.

Andy

70ZZ3 96LT4

Do you know how to remove an alternator and take it apart? Replace the voltage regulator inside the alternator. Not difficult. The voltage regulator is the unit that has the two terminals that stick up that the connector plug attaches to. You will need to suspend the brushes in a retracted position to assemble the alternator. I toothpick will work. After it is assembled remove the toothpick. Pay attention to the insulated screws that retain the voltage regulator. Over the years in maintaining my original owner 1970, I have replaced the voltage regulator a few times.

7T1vette

How much "overcharging" are you talking about? When the battery is fully charged, the alternator still puts out nearly 13 volts. You will never see an auto alternator putting out only 12 volts...unless the idle is so slow that it can't develop a charge.

If it overcharges to nearly 15 volts, the regulator [in the alternator] isn't functioning.

racegofast

1st take a multi meter and test the true output of the alt. that way you know your not just throwing money away. start the car and test at the batt,or at any conveniant pos/neg place.If your charging over 14 volts your reg is prob bad. you can buy a new chrom alt 120 amp on e bay for about 70 bucks skip white. good luck. always test before you replace.

tfi racing

Factory guages can be very inaccurate,check output with a known good meter before throwing money at it.You could have a bad alt,guage or wiring issue anywhere in between.

AT-82Collectors

I should have been more complete in my reply. The others that have replied are correct, test it or have it tested first. In my case the headlights went bright and I smelled the battery overcharging. Good luck.

Andy

racegofast

change the regulator or buy that new one.

uwish

Thanks everyone for the help having the altenator rebuilt . The Problem I'm having now is the passenger seat will not fold down it seems to be caught on the inside near the center consol . I want get it out to have it reupholsered . Thanks again

MotorHead

Lot of misinformation out there, 14.5V is fine for alternator output measured at the battery with the engine running, should have put a voltmeter on the battery first before having things rebuilt or replaced.

racegofast

yeah dont forget that .5 volt

bigvette1

The range for a good alternator at about 1000 rpm's is 13.7 to 14.2 measured at the +12vdc terminal on the back of the alternator to ground on the alternator with a digital volt meter. At the battery expect .3-.5v drop due to line loss of the cables and connectors. Beyond 14.2 get a new one as you will cook the battery!