Can you electrically test a ground?

[JammerX19]

I mean, it's obvious that continuity is a fair test but when it comes down to a ground being good enough to handle a sizable amount of current, how do you test that?

[baltobernie]

Measure the resistance (ohms) in the circuit.

[RRoller123]

Assumming a good connection to the chassis (~zero ohms) the limitation is the gauge of the wire and type of connector. Faston Spade type connectors are generally poor over time due to low contact force and area. Prone to corrosion. A screw down Ring type connector is better. That being said, no connector manufacturer wants to make a connector that can't carry the current that the wire it is attached to can carry, so they are all rated to at least match the wire capacity. Not ethat wire capacity is temperature dependent.

Here are a couple of resources:

Here's a great resource for AWG data and info regarding current capacity:

http://en.wikipedia.org/wiki/American_wire_gauge

Here's a great calculator for DC current/volt/amp calculations as well:

http://www.sengpielaudio.com/calculator-ohmslaw.htm

[So Cal Mark]

a continuity test won't show the capacity of the circuit, do a voltage drop test at each connection

[majicwrench]

Take a voltmeter, turn the circuit on, put one lead on the battery (-) and other lead on the ground. In a perfect world it would show no volts. It will likely show a tiny amount of current, due to the tiny amount of resistance in the ground connections. Say .02 volts. The worse the connection, the higher the volts will go.
You have now tested the ground under load.

[spider2081]

Checking for voltage drops across circuit connections is a great troubleshooting step or procedure. To be done most effectively maximum current should be flowing through the connection. Example if you are checking the headlight ground spade connection at the spider the headlight bulb must be in the circuit and turned on. Voltage = Current X Resistance. If the headlight is not in circuit and turned on there is no current flow so no voltage drop across the connection.
Measuring ground connections with the ohm meter is difficult because even small amount of resistance can cause a considerable voltage drop if enough current flows through the connection. Measuring the voltage developed across the connection (voltage drop) while the circuit is operating is a doable meaningful test.

Hope this helps