Hello, Im new to the forum. I have an over voltage issue. Went to start the car and it was a weak start. turned it off and battery was dead. i put it on the charger in start mode and got it running again. voltage was at about 15.3v. i find that to be high. I took it to Oreillys for a alternator check. Alternator was charging about 13.8 she said. according to them alternator was good, 4 year old battery was bad. I had an issue with corrosion and acid around the positive post a few months ago. any with a new battery im still at idle getting about 15.2 volts. not sure whats going on. alternator is 3 years two months old installed at a dealership. figures im right out of warranty. any ideas? maybe its the voltage regulator? The power steering pump has a minor leak, perhaps that is getting in the alternator and causing a problem? sorry for the long post...I need help.

 

What does your volt meter read when you measure across the battery posts when the engine isn't running?

 

Right now battery is 13.2V with no key in the ignition.

 

The battery should be 12.6V, so something is wrong with your volt meter. Check that the meter leads are not corroded where they connect to the meter. Try another meter if available.

You can also test you meter on a 9V battery or some other common batteries like AA, C, etc.

 

My meter said a 9 volt battery was 8 volts. And it was a good battery according to the tounge test.

 

Probably a good time to get a new volt meter. You can get an inexpensive one at most big-box stores.