volt gauge reads 18volts and sometimes in the red

[98blackbeauty]

1995 friebird formula Lt1. Just got the car first thought it was battry, I swapped battry's and the condition the same. When I start the car it turns right over and battry gauge goes up to 18 or in the red. sometimes after running a while it comes down slightly, but never around 13-13.5. I swapped altenators and it still does the same thing. Took the original altenator to murrays had them check it. It checks fine. I then drove about 10 - 12 miles gauge never dropped but needle width below 18. ???
I'm puzzeled.

[Robert Lawler]

Shorted wire, bad gage. Thats my guess.

[Z28ISGR8]

I don't have quite the same problem, i.e my needle never is in the red. But it isn't at 13 either, prolly around 15 16. My car turns over no matter what and runs like a champ. Although now I'm gonna go to Murray's to get my alternator checked out because my battery is less than 2 years old.

[c0ncEpT]

I don't have quite the same problem, i.e my needle never is in the red. But it isn't at 13 either, prolly around 15 16. My car turns over no matter what and runs like a champ. Although now I'm gonna go to Murray's to get my alternator checked out because my battery is less than 2 years old.

My car is the same. If you have the keyed on but not running it will read right around 12. After you start it it reads like 15-16ish. I never saw it as a problem.

[lozanoa11]

uh yea thats not a good thing. but put a volt meeter on the battery when its running to see what it is. It should be between like 13.4 and 14.7 or someting like that.

[Z28ISGR8]

uh yea thats not a good thing. but put a volt meeter on the battery when its running to see what it is. It should be between like 13.4 and 14.7 or someting like that.

Why is it so bad??

[c0ncEpT]

Why is it so bad??

Overcharging can begin to fry your electronics

[lozanoa11]

b/c if your alt is putting out that much it will soon burn out. It means it is over working. Usaly the regulator is at falt but they are integrated in most of the newer alts. It is most likely a bad gauge.

If you turn ur car on and then disconnected your battery (in a pre computer controlled car) The alt would try to compensate for the low voltatge. This will evetuly fry a alt. So if it is makeing that much voltage you have a problem.
but it probaly isnt. The stock gauges blow lol

[Z28ISGR8]

uh yea thats not a good thing. but put a volt meeter on the battery when its running to see what it is. It should be between like 13.4 and 14.7 or someting like that.

So if it reads somewhere in there that it's prolly the gauge that's messed up?

[MP81]

Yeah, check the voltage at the battery, and check the output of the alternator.

[98blackbeauty]

I started the car, gauge inside says 17.5 or more. Meter across battry terminals reads 13.5 14.0.

[MP81]

Try checking the voltage of something in the car.

[meissen]

I started the car, gauge inside says 17.5 or more. Meter across battry terminals reads 13.5 14.0.

When the hell did you do this? You've been inside since I got home.

[MP81]

Or has he...?

[Casey]

I started the car, gauge inside says 17.5 or more. Meter across battry terminals reads 13.5 14.0.

I'd say you're fine then. I assume all your electronics are working normally? My friend's talon was getting an overcharge and his windows would go fully up and down in less than a second. New alt fixed his problem. You're probably just another victim to a shitty stock GM gauge.