94 Olds Cutlass Supreme high volt reading

[Dastardly]

I've just noticed that the voltage gage is showing the car is almost putting out 18 volts? I don't know much about how much voltage it's spose to put out but I'm certain that is too much. It only puts that much out while the car is running.

If I just turn the key over but don't start it shows the battery volts to be normal, but while the car is running it's very high.

So I ask what would cause the voltage to be so high?

Oh by the way its a 1994 oldsmobile Cutlass Supreme SL 3.1 V6

[xeroinfinity]

If your battery is low then it should be charging a higher voltage until its power is brought up.

I'd check the battery voltage, should be 12.4-13.5 volts with the car off. More volts when running, up to 14v.
I'd also check the battery cables and make sure they are clean and tight!!

Hope that helps

[Dastardly]

Thank you for the quick response xeroinfinity.

I had Advance Auto check the alternator and battery, the battery checkd good, but their machine said said the alternator is putting out 175Amps and is spose to put out only 105Amps, so I guess I will be replacing the alternator.

Also the battery cables, and such are clean and tight.

I have a question, the pully spindal thing that is on the altenator, do you need a socket to get it off? Or how exactly is it removed?

[Dastardly]

Update

Well I put a new alternator on today. The voltage on the guage still seems to be high. The needle for the guage is really close to the red.

Any thoughts?

[Dastardly]

Bump!

The voltage on my car is still very high. All cables cleaned, and look nice, new alternator, why would it still put high volts? I turn the key on voltage for the battery is always good, starts with No problems. I know the battery is 5 years old, so could the battery for any reason be causing the alternator "while running" to put out almost 18 volts!

Please help.

Also if anyone can some advice, the idle goes crazy sometimes, I've cleaned the TPS before and seemed to help for a one time deal, but the car idles low, should i replaced the TPS?

Thanks

[xeroinfinity]

yeah, a bad battery will cause the alternator to be on constant highoutput.
That would have been one of the first things I'd hav tested & replaced, much cheaper then an alternator.

On your irratic/low idle,
check that you dont have a cracked vacum line.
Also you might test/clean the IAC , and the pocket it sets in.

[tom44127]

how old would you say the tps is if it is the org. then replace it.did this on my 93 help with the idle issue.

[Dastardly]

Originally Posted by tom44127

how old would you say the tps is if it is the org. then replace it.did this on my 93 help with the idle issue.

Yeah it's the orignal TPS, probably will replace it.


Also I put a new battery on... still has high voltage reading... I have no idea what is causing it, just seemed like it started for unknown reasons.

[xeroinfinity]

Ok, I'd ignore the dash gauge, get a volt meter and test the battery voltage while the engine is running, also check it at the alternator.

Their are several fuseable links down by the starter, if on of them is blown your charging/starting system will have problems.

Good Luck