Battery problem

[Dragk913]

Ok, when I was driving to school today, my voltmeter shot up to 18 [it normally stays at around 14 when driving], the battery light, and the light that looks like a car with its headlights on came on. I stopped and turned off the car then restarted it. When I started it, it was fine but then when I got on the gas, the voltmeter would shoot up to 18 and the little light came back on.


I tried searching but I'm at school and don't have a lot of time to be on the computer.


So, if anyone could help me think of what it might be, I would be in your debt

Also, will it be ok if I drive it home [about 15miles]?


Thanks a lot!!

 

[Dragk913]

Well I had more time to search around and...I've narrowed it down to a crappy battery, alternator, or wires.

But I can't check much at school so now I just need to know if it would be safe for me to drive it home?

 

[jdub]

The voltage regulator is inside the alternator...sounds like yours is done. Take it by a parts store and have them test it on your way home.

 

[Dragk913]

The voltage regulator is inside the alternator...sounds like yours is done. Take it by a parts store and have them test it on your way home.

Alrighty, thanks for the input.
But it will be safe driving for a couple miles, right?
[Sorry, I just got done rebuilding the engine and I'm scared of anything happening to it:icon_cry:

 

[NeatOman]

You could bump into an electrical fire.

 

[jetjock]

The voltage regulator is inside the alternator...sounds like yours is done. Take it by a parts store and have them test it on your way home.

^ Agreed.

You're losing regulation. Check the wiring on the alternator and battery, especially the sense wire. It's the smallish one connected to the positive battery post. Also check the engine block ground. If all that checks out replace the alternator. You could replace just the regulator (easy) if that's what it turns out to be but if the alternator is high time you should replace the entire thing.

Whatever it is track it down soon because 18 volts is pushing it. You run the risk of damaging the battery, lamps (you may have already popped some tail or brake lights), radio, maybe even your ECU. It's a crap shoot. Myself, I wouldn't drive the car in this condition. You could drive it on the battery alone but you risk not making it home. That said a couple of miles won't be a problem. 15 is probably going to be.

Lastly, unless you put one in the car doesn't have an amp gage. You're refering to the voltmeter.

 

[Dragk913]

^ Agreed.

You're losing regulation. Check the wiring on the alternator and battery, especially the sense wire. It's the smallish one connected to the positive battery post. Also check the engine block ground. If all that checks out replace the alternator. You could replace just the regulator (easy) if that's what it turns out to be but if the alternator is high time you should replace the entire thing.

Whatever it is track it down soon because 18 volts is pushing it. You run the risk of damaging the battery, lamps (you may have already popped some tail or brake lights), radio, maybe even your ECU. It's a crap shoot. Myself, I wouldn't drive the car in this condition. You could drive it on the battery alone but you risk not making it home. That said a couple of miles won't be a problem. 15 is probably going to be.

Lastly, unless you put one in the car doesn't have an amp gage. You're refering to the voltmeter.

Man, that's lame. Thanks for the help.

There is an O'Reilly's less than 1/4 of a mile from my school so I guess I'll run over there. Let's just hope I don't have an electrical fire during that time



Thanks again!

 

[Silvasoup]

When your voltage regulator goes don't you have to replace the alternator too as it is a one unit item? Or can you replace just the regulator?

 

[6o4turbo]

When your voltage regulator goes don't you have to replace the alternator too as it is a one unit item? Or can you replace just the regulator?

Yes you can replace the regulator seperately, and it isn't a very difficult procedure.

 

[jetjock]

^ What he said. It's not as easy as replacing the brushes but it's not all that hard to do since it just bolts on. Whether it's worth it or not is open for debate.

Since I dislike the junk most auto stores sell I roll my own rebuilds. As long as the stator and field windings are OK it's not that hard to do even without the nice instructions in the TRSM. Disassemble, clean, check diodes and windings, replace bearings, brushes, polish the slip rings, reassemble. Done. I've overhauled my original once already, at 100K miles. It's now 45K beyond that.

While we're talking alternators by far the single greatest reasons for high time failures are brushes or bearings with brushes coming in first. That's a shame because on this one they're simple and cheap to replace. The problem is you need to replace them *before* they go bad. Once they're completely gone the springs will chew up the slip rings they ride on. Replacing the brushes after this happens will cause the new ones to be eaten like candy. In that case the alternator will need to be opened up and the slip rings turned/polished.

Course, a bad bearing always requires disassembly but as long as the bearings are OK changing the brushes every 75K miles or so usually results in a long lived alternator. That is, unless something else happens to it .

 

[zdaeng]

Better changed the alternator man OR you will risk burning your car!

It happened to me once when i'm driving my Celica RA60.
Actually i just replaced a recond alternator and i'm driving back home. Suddenly the volt meter increased to 18. While driving, i can hear a hisssing sound came from the alternator and the sound keeps increasing each time I slam the gas paddle. After 15km from my mechanic workshop, I smell something burning from my speedo meter and my car stall.

Tried to start the car but it won't start and I have to tow the car back to the workshop. Upon checking, all the bulbs (signal bulb, head lamp and etc)are burn and also I have to replace my speedometer. As this is the mechanic fault, he has replaced everything without charging me.

 

[Dragk913]

Better changed the alternator man OR you will risk burning your car!

Tried to start the car but it won't start and I have to tow the car back to the workshop. Upon checking, all the bulbs (signal bulb, head lamp and etc)are burn and also I have to replace my speedometer. As this is the mechanic fault, he has replaced everything without charging me.

Wow, I'm glad I went to O'reilly's


I just want to say thank you to all the people who helped
I went to O'Reilly's and tested my alternator...the result: Dead, Dead, Dead. So I bought a new one, threw it on and everything was fine.