i want to know how accurate it is because i would drive around and see it move from 12-14v. it will stay at 12 for about a block or 2 then move up stay, then drop, etc. i would turn off the car it would be able to start again. looked at the alt. looks like it was bought at a junkyard (seen the markings). the car drives fine, so would it be the alt. or the gauge?
thanks

 

Could be either one, but i wouldn't trust the stock guages. Pull your your DMM and check your voltage between the negative and the positive while the car is running. Should be abround 13.5 V.

 

oh yea i also wanted to note that it is a s4 and only does it at night. doesnt do it in day time (only radio on)

 

Mine isn't accurate at all. It always sits right around 12v (if I had to guess 11.8-12.4v). Yet, in the 8 months it's done that I've yet to have a battery go dead which defies reason if the gauge was actually working right.

 

Why don't you get an aftermarket voltmeter or a DMM and verify this yourself?


-Ted

 

^^^
+1!

 

How is "Acurate enough." for an answer?

If you are needing something more acurate you should be using a DMM anyway.

The stock gauge is just there to tell you what is "Normal" and if it is otherwise...

 

new temp gauge for my s4 it is. im glad my s5 dont have lil problems like this. every needle sits where it suppose to

 

mine is very accurate actually, i was having some mysterious battery draining problems, i fixed it, but all throughout the problem time my voltage gauge never lied to me, even compared to a mulitmeter.

 

i was wondering what your problem was so i can also take alook at it on my car just make make sure
thanks

 

well it required a lot of wire hunting. i had a short on one of the ground wires connected to the body. i just pulled fuses untill i found what was drawing the current.

 

My voltage rises and falls depending on the electrical load. If nothing but my radio, it stays above the 12 mark. But once I flip on the headlights, it goes down slightly but still over 12V. But if i have the heater, rear defrost, and headlights, it drops to 12V. But when you are crusing along it stays up but when you are at an idle the voltage drops down an everything dims a touch. Its probably due to poor grounding. I have a new alt. and battery which helped. But its still there, just not as bad.