Battery voltage drops while driving, unless revved above 3.5k or so.

[jlado13]

When I start driving, the voltage will progressively drop, all the way down into the 9v area, causing my stereo and AFC to shut off... This is if the rpms stay relatively low to average. However, if I give it a quick rev above 3.5k or so, the battery quickly charges to 14volts and then it is good for the rest of the drive. The alternator is new, but the wiring seems to be kinda sketchy. Any suggestions? Does anyone have an alternator wiring diagram?

 

[justoscar1]

it might just be a bad battery...i had the same problem....got a new battery and no more problem

 

[Silver 95 GST]

How is the wiring "sketchy"? Make sure the wire housing ins't melted or worn off the wires. If it is electrical tape it. I think it's pretty hard to miswire an alternator.

ALso go to an autoparts store and get your battery and alternator tested. They can do it right onthe car.

 

[ccb21]

it might just be a bad battery...i had the same problem....got a new battery and no more problem

Agreed, simple fix most likly, also do you have an amp ect attached to it?

 

[jlado13]

I've been through 3 batteries in six months or so... So I definitely think battery is out of the question. This is my 2nd alternator and it has already tested good, sorry I forgot to add that. The plastic on the main connector to the alternator is a little deformed from heat. I bought this car with this problem and the wiring was as is. I have a couple small wires dangling under the alternator that I don't know where they go. And I already have the small one hooked up on the power steering pump.

Thanks for your suggestions so far!

 

[edwards95gst]

i am haing this same problem.. also the other day when i got home from drving for like 30 min i shut my car off and hurd a fizzing noise comeing from the battery and i took it out and the battery was all bubbled out...?? any one know what this could be.. it has a brand new battery too. its a 95 gst too btw.... thanks

 

[DGajre777]

Here is some info - http://www.dsmtuners.com/forums/art...55-alternator-issues-brake-battery-light.html

I've been through 3 batteries in six months or so... So I definitely think battery is out of the question. This is my 2nd alternator and it has already tested good, sorry I forgot to add that. The plastic on the main connector to the alternator is a little deformed from heat. I bought this car with this problem and the wiring was as is. I have a couple small wires dangling under the alternator that I don't know where they go. And I already have the small one hooked up on the power steering pump.

Thanks for your suggestions so far!

Just because the alternator is tested and provides volts/amps during a test doesn't mean that the voltage regulator is in good condition. Eventually, the voltage regulator will be dead and it won't bump up the "juice" at low RPM to charge the battery.

i am haing this same problem.. also the other day when i got home from drving for like 30 min i shut my car off and hurd a fizzing noise comeing from the battery and i took it out and the battery was all bubbled out...?? any one know what this could be.. it has a brand new battery too. its a 95 gst too btw.... thanks

In your case, the voltage regulator is overcharging the battery or you have a really cheap Autozone Silver type battery.

 

[1whitegsx]

Alternator! dont get one from autozone or advanced though. go factory. its more expensive but it def lasts longer. i had one from advanced and a year later it was on the back of a tow truck. spend the extra money.

 

[blcknspo0ln]

I've been having the same issues for the past year. Let's count, FOUR batteries and FIVE alternators (both duralast from autozone). All of which tested fine and then eventually tested bad. My new symptom (both alt and battery have less than 150 miles) is that the car will hang around 10v upon cold start, revving to 4k will 'kick in the juice' and it will stay at 14V. 20 miles down the road, it'll start dropping to 10V. I drove it home the other day and all of a sudden it just went back to 14V and stayed there?

I don't get it either. After money is good again, a new optima battery and oem alternator will be on order.

 

[DGajre777]

My OEM battery and OEM alternator have been good to me for the last 2 years.

 

[1992GSX]

I had a similar problem, not so severe to where things would shut off while I was driving. I replaced my alternator 4 to 6 weeks ago and about a week ago I started experiencing similar symptoms as you are, plus dash lights and all that.

Turned out it was the internal regulator, the alternator was charging fine, but this will eventually cause it to go bad. Luckily, I got mine with a lifetime warranty. Got the replacement, bolted it up and I was good.

Lesson learned: Do it once, do it right. Pay the extra for a good part so you dont have to worry about in a few months or a year down the road.