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?

[Spoke]

Ohms law says it all: V = I x R

With current (I) and resistance ®, a voltage drop (V) happens. When this voltage drop happens to and from the intended load (head lights, turn signals, fuel pump, etc), your load sees less voltage than at the battery.

The wiring is resistive ®, the old, oxidized spade connectors on the fuse panel are resistive ®, every ground and power lug connection can get oxidized and act resistive ®.

You can't do much about the wiring but you can clean all the ground and power connectors. This will help minimize the voltage drops but will not eliminate them.

You can also get a layer of oxidation between the battery terminal and its connector. I had trouble starting my car, checked the battery connectors and they were tight. When the car wouldn't start, I turned the headlights on and measured about 8V drop between the battery positive terminal and its connector. Cleaned that one off and never had trouble starting after that.