Voltmeter gauge drops under 11 volts, Readings decrease when loads are applied Options

[championgt1]

Installed a new battery and started the car. Voltmeter gauge reads around 13 volts. Cool. Turn the headlights on, gauge reads about 12. Cool. Hit the brake pedal gauge now drops below 11. Not cool.

The owners manual says the gauge should stay between 12 and 14 with loads applied. Mine is dropping below 11.

Any ideas? Bad Ground?

[jim_hoyland]

I went through the same thing. Finally wired the battery and volt meter to a relay and used a wire from the fuse panel to turn the relay on upon starting. Now I get a direct reading from the battery.

If the relay is mounted in the engine bay, the coil wire could be used to activate the relay.

30 = Battery in
87 = Wire to voltmeter
85 = Fuse panel hot, or coil hot
86 = Ground

[jk76.914]

I went through the same thing. Finally wired the battery and volt meter to a relay and used a wire from the fuse panel to turn the relay on upon starting. Now I get a direct reading from the battery.

If the relay is mounted in the engine bay, the coil wire could be used to activate the relay.

30 = Battery in
87 = Wire to voltmeter
85 = Fuse panel hot, or coil hot
86 = Ground

I did the exact same thing. Except I put the relay in the console, and used the wire that used to go to the voltmeter to activate the relay. That's a "fuse panel hot" line, as Jim described.

In either case, you have to run a new single wire from the battery to the voltmeter. It can be pretty small gauge, as there is only the tiny load of the voltmeter on it. You need the relay to be sure no current is going to the volt meter when the ignition is off, so you don't slowly drain the battery through the meter.