The alternator tested at 28 volts. I have charge to battery up every couple of weeks. It does not boil. Maybe the tester made a mistake. The car is a 1986 Subaru wagon.

Thanks,

abcus

What exactly is the car doing? Does the battery not stay charged while the car runs?

 

28 volts? It should regulate itself to 13.5-14.5.

The one I just replaced out of Mad Max was putting out 20-21 volts.

 

Your asking to fry something with that many volts.

 

The junkyard one I replaced it with puts out 14 volts.

 

REPLACE your alternator!

Glenn

82 SubaruHummer

84 GL Mad Max

01 Forester

The alternator tested at 28 volts. I have charge to battery up every couple of weeks. It does not boil. Maybe the tester made a mistake. The car is a 1986 Subaru wagon.

Thanks,

abcus

 

What would cause an alternator increase voltage output?

What would cause an alternator increase voltage output?

 

Voltage regulator not regulating it at 14 volts. Alternators increase voltage with RPMs; thats how they work. The regulator keeps them at a safe level so you dont fry out your 12vdc circuts.

when the regulators die they ground the field. then the alternator charges at wide open throttle.

what did the guys tell you that tested it? did they try to sell you a new one?

 

replacing the regulator is a pain in the rump roast, id just swap it out for another junkyard alternator.

 

didnt you notice your tach doin funny stuff? among other crazyness caused by 20 volts?

The tip off should have been when your headlights got real bright just before they burned out! 28V is unbelievably high.

What exactly is the car doing? Does the battery not stay charged while the car runs?

 

28 volts? It should regulate itself to 13.5-14.5.

Dear Snowman,

When I am driving the guage shows 8 volts. After a few weeks the car will not start and I have to charger the battery up.

Thanks,

abcus

when the regulators die they ground the field. then the alternator charges at wide open throttle.

what did the guys tell you that tested it? did they try to sell you a new one?

 

replacing the regulator is a pain in the rump roast, id just swap it out for another junkyard alternator.

 

didnt you notice your tach doin funny stuff? among other crazyness caused by 20 volts?

Dear A,

The guys did try to sell me a new one for 120 dollars.I said it did not make sense since the battery was not boiling and i was having to charge it up every so often. Can not remember the tach flucuating a lot but i do not drive the car regularly.

Are you sure he didn't say something that sounded like 28, but could have been 8? If it was putting out 28 volts you'd be having all kinds of burned out bulbs and you voltmeter should be way off scale hi. But, if it's putting out 8 volts as your meter reads you'd have just the problem it sounds like you have.

My hypothesis is that the wire from the alternator to the battery is bad, or the fusible link is bad. Even if the alternator itself is putting out 28 volts, a very small amount if any is getting to the rest of the electrical system (I tested a 66 Ford van that was putting out up to 72 volts at the alternator but measured 10 at the battery). The bad wiring may have caused the alternator to crank up the voltage to try to continue charging the battery, which could have fried the regulator.

 

Hope this helps.

When my battery went dry in my 78 wagon the voltage regulator (external)

freiked out, fried my Radar detecter and popped the headlights.

Sumthing to consider.

Dear KStretch55,

I ended up getting a rebuilt alternator . The internal voltage regulator must have gone out. The car seems to be working normally now. Thanks to all the folks who helped me deal with my problem. Now, I have to try to get it through California smog testing.

Thanks,

abcus

Thats good you got that sorted out.Good luck, i hope you pass