Well I just finished rebuilding my motor last week and my battery dies this week. Now that I have changed my battery about a 30 secs after start up the Voltage gauge jumps to 18v. I have no clue wha tis causing this. I checked all my electrical connections for corrosion ( even in the wire under insulation).

Anyone have any idea what could be causing this. The very last thing I did before this started was pluged my rear o2 sensors in on the stock manifolds.

 

Check the voltage at the battery. Does that voltage stay on 18V also?? If so, don't run the car because it is overcharging the battery. When the battery gets hot, the battery will start venting hydrogen and I don't have to explain to you why this is dangerous (Hindenburg??) If you still continue to charge it, the acid will boil and spray everywhere (not a good thing either ... ) It's obviously also bad for your battery...

This situation is most likely caused by the voltage regulator crapping out, I think it's built in in the alternator on our cars, so you may have to change it out. There may be a way to change just the regulator, but I am not sure on that.

Be careful!

Sam

 

i had this happen in my truck once, i was driving home late one night and my lights got super bright and my dash lit up the cab like daylight then the truck died as i pulled into the driveway, the battery was cooked, bad voltage regulator.

 

depending on the cost of a voltage regulator, u might be just as good to get a new alternator.. and its alot faster of a swap ..

I just put a red top optima battery in my car.. seems to work good

 

The only thing that could cause over voltage is the alternator. Over voltage can wreak havoc on the wiring and electrical components. It can cause trouble that you may hunt for a long time. I would fix it right away.

The voltage regulator is inside the alt. You can replace it by itselft, but it is not cheap. Probably more worth it to replace the alt, especially if there a number of miles on it. Faster to replace the whole thing as 93Z286Speed already mentioned.

 

I agree,i had this problem with my winter car and cooked a battery.Just use a volt meter on the battery with the car running and if it reads more than 14.7 volts than just get a rebuilt alternator.

 

Thanks for all the replies. I just checked with the local autozone and they infact do make a replacement voltage regulator. Now if I take my altenator down there and have it tested will it show that its bad?