Battery Gauge Meter

[DaChevyClassic]

When I hit the brakes I can see my battery gauge meter twitch a little. My battery gauge meter keep waving back and forth when I get off the gas at a low RPM. What this can be?

[gmtech1]

Could be low alternator output. A little movement when a electrical load is added the system, such as brake lights, head lights, ect...is normal.

[j cAT]

Originally Posted by DaChevyClassic

When I hit the brakes I can see my battery gauge meter twitch a little. My battery gauge meter keep waving back and forth when I get off the gas at a low RPM. What this can be?

have the battery load tested. this can be done free at most auto part stores. make sure the battery connections and cables are clean and free from the green corrosion. also check grounds.

with a voltmeter at the battery measure the voltage with the engine running, no lights,ac etc on. then turn on ac lights heater/ac blower to max and the voltage should not drop.

If the voltage drops or pulses this would indicate a bad regulator/diode assy of the alternator.

the voltage should be 13.5 volts at 100deg f . the voltage at 70 deg f will be about 14.25 volts. this is with a engine at normal operating temperture at idle.

THE VOLTAGE SHOULD NOT VARY WITH RPM OR NORMAL VEHICLE electrical LOADS AS BUILT.

If you have an aftermarket HI POWER sound system this would overload the alternator output ability and you will see a change in voltage.