I just installed my volt meter gauge and when it is turned on it reads way over 18 volts is that correct. I thought a car battery runs 12 volts. I just want to make sure that the gauge is working correctly.

 

with the car running, it should read about 14volts.

 

with it running it reads way over 18 it is like the needel is pegged all the way when the gauge is on.

 

Check the install or maybe a f-ed up gauge. Like said above when the car is on it should measure approximately 14 but should always be btw approx 12-14 depending on what you have on, like a/c, lights, system, etc. If your car was running on 18volts then your alternator is overcharging and can cause you battery to burst. First check install, then test voltage output on alternator, if all is ok then gauge is no good. Good luck. One.

 

Thanks for the heads up

 

It sounds like the alternator is being full-fielded or the regulator shorted. Have you checked the wiring from the alternator to the ECU?

Make sure that each wire in the alternator connector has continuity to the corresponding wire at the ECU.
Make sure that each wire is not shorted to ground.
Make sure your grounding points [all of them] are clean and tight.
Check ELD output voltages with various loads turned on: the voltage should decrease as loads are turned on.

Other than this...Its Helms time.

 

Well I tried another battery and it reads 9 volts so I am guessing that the gauge is working