Well the last couple days my "check charging system" light has been coming on so I went out today and my car is only charging at around 11 volts.. its driving and staring fine so I dont understand.

I haven't had any audio in my car for months now which makes it even more weird. . Right now I have a 220 amp alt and just 2 of my batts in the car.

Could this only be the alt messing up? Is there anything I can check before I swap alts?

What kind of car is it? Some newer cars have duty cycle that reports to the ECM.

05 murcury sable

whos the maker of the alt?

Most common thing I can think of is the main fuse on the side of the under hood fuse block.

Most common thing I can think of is the main fuse on the side of the under hood fuse block.

The "mega fuse" . . . . If that's what your talking about your not able to see if its blown.(will need to replace to check).... But if it blew would the car even start?

Yes. It's seperate wires to the starter and fuses. Just lift the cover and check for voltage on both bolts.

whos the maker of the alt?

Its a "powerbastards" alt. . I know its not the best but has done me good running an aq3500 at .5 (with good wiring and batts). . Had no problems for a couple years of running it. . And now have only had the front stage installed for a few months

There is also a 30a fuse for the exciter wire. It's under the hood just not sure where beyond that.

Edited May 11, 201411 yr by puscifer2

I'm not sure on how your big 3 is done but the mega fuse may not even be used. If you ran a new wire from the alt directly to the battery then check the fuse in that wire instead.

I'm not sure on how your big 3 is done but the mega fuse may not even be used. If you ran a new wire from the alt directly to the battery then check the fuse in that wire instead.

I did the alt/+ wire of my big 3 through the megafuse

Did you change the fuse at that time? I think it's only rated at 175a

 

whos the maker of the alt?

Its a "powerbastards" alt. . I know its not the best but has done me good running an aq3500 at .5 (with good wiring and batts). . Had no problems for a couple years of running it. . And now have only had the front stage installed for a few months

 

Damn it made it that long kool, I have a Mechman 270A alt and it does the same thing its a year old.

no belt slip and new tensioner and still have voltege problems but starts and runs fine.

 My alt started doing this 3 months ago. so i went with singer.im waiting on my new alt to replace it.

But any way check with every thing like the other guys are telling you on this form before you buy another alt.

by the way, I never had a alt last for more then 2 years lol

Checked voltage at alt. At batt and each side of the mega fuse. All reads right around the high 10s low 11s. That's with the vehicle on

Check for batt voltage at the alt with the key off. If that's good then check the 30a fuse for the exciter. If they are both good then it's the alt that's bad.

Check for batt voltage at the alt with the key off. If that's good then check the 30a fuse for the exciter. If they are both good then it's the alt that's bad.

Would it be the "alt fuse" your talking about?. If so. that fuse is good

 

Check for batt voltage at the alt with the key off. If that's good then check the 30a fuse for the exciter. If they are both good then it's the alt that's bad.

Would it be the "alt fuse" your talking about?. If so. that fuse is good

 

Maybe bad battery?

 

But I'd be the first person to point at the alt, a few years when I inquired about an alternator from them they gave me some off the wall answers.

Check for batt voltage at the alt with the key off. If that's good then check the 30a fuse for the exciter. If they are both good then it's the alt that's bad.

Would it be the "alt fuse" your talking about?. If so. that fuse is good

Maybe bad battery?

 

But I'd be the first person to point at the alt, a few years when I inquired about an alternator from them they gave me some off the wall answers.

Wouldn't the car charge nornal once running even with bad batt?

 

 

 

Check for batt voltage at the alt with the key off. If that's good then check the 30a fuse for the exciter. If they are both good then it's the alt that's bad.

Would it be the "alt fuse" your talking about?. If so. that fuse is good

Maybe bad battery?

 

But I'd be the first person to point at the alt, a few years when I inquired about an alternator from them they gave me some off the wall answers.

Wouldn't the car charge nornal once running even with bad batt?

 

It could have a bad cell or something, so your its a parasitic drain so your alt is trying to charge it dropping low voltage. Maybe.

 

All speculation really, try removing stuff one at a time then start adding to see if you can limit it to one thing.

The batts sit at right around 12 when the car is off

The batts sit at right around 12 when the car is off

start the car and the disconect the postive off your battery, the car stays running then check your voltege on the alt.

the battery is only for starting the car, the alternator is the one that keeps your car on and charges your battery untill its knows that the battery is fully charged. the voltege should be above 13 or 14 volts when you have the battery disconected. 

if your car turns off when you disconect the Battery then you have a Bad Alternator.

also when you disconect the battery  and the car stays on but the car struggles to stay on then your Alternator is half azz workn and will go out soon

Edited May 12, 201411 yr by Cruz87

The batts sit at right around 12 when the car is off

start the car and the disconect the postive off your battery, the car stays running then check your voltege on the alt.

the battery is only for starting the car, the alternator is the one that keeps your car on and charges your battery untill its knows that the battery is fully charged. the voltege should be above 13 or 14 volts when you have the battery disconected. 

if your car turns off when you disconect the Battery then you have a Bad Alternator.

also when you disconect the battery  and the car stays on but the car struggles to stay on then your Alternator is half azz workn and will go out soon

That's what I was about to do. . Im kinda thinking its the alt going out but every time I have had an alt mess up it just stopped working all together in one day. . . . . . I have been wanting upgrade alts again for a while now so this mite be the motivation to do it lol. Still sucks though

 

 

The batts sit at right around 12 when the car is off

start the car and the disconect the postive off your battery, the car stays running then check your voltege on the alt.

the battery is only for starting the car, the alternator is the one that keeps your car on and charges your battery untill its knows that the battery is fully charged. the voltege should be above 13 or 14 volts when you have the battery disconected. 

if your car turns off when you disconect the Battery then you have a Bad Alternator.

also when you disconect the battery  and the car stays on but the car struggles to stay on then your Alternator is half azz workn and will go out soon

That's what I was about to do. . Im kinda thinking its the alt going out but every time I have had an alt mess up it just stopped working all together in one day. . . . . . I have been wanting upgrade alts again for a while now so this mite be the motivation to do it lol. Still sucks though

 

i know it sucks to spend money on a  new alternator bro, ask singer if he can rebuild it.

but then again could cost as much on buying a new one instead , with shipping to and back can cost and then parts for repair and labor will probably add up for a new one 

hope you get your electical fixed 

The batts sit at right around 12 when the car is off

start the car and the disconect the postive off your battery, the car stays running then check your voltege on the alt.

the battery is only for starting the car, the alternator is the one that keeps your car on and charges your battery untill its knows that the battery is fully charged. the voltege should be above 13 or 14 volts when you have the battery disconected. 

if your car turns off when you disconect the Battery then you have a Bad Alternator.

also when you disconect the battery  and the car stays on but the car struggles to stay on then your Alternator is half azz workn and will go out soon

That's what I was about to do. . Im kinda thinking its the alt going out but every time I have had an alt mess up it just stopped working all together in one day. . . . . . I have been wanting upgrade alts again for a while now so this mite be the motivation to do it lol. Still sucks though

i know it sucks to spend money on a  new alternator bro, ask singer if he can rebuild it.

but then again could cost as much on buying a new one instead , with shipping to and back can cost and then parts for repair and labor will probably add up for a new one 

hope you get your electical fixed

I have talked to him a couple time and he said the most he could do is 200 amp for my car and im forsure going to want more than I had if I upgrade again

Sounds like your PCM regulator is going out. The same thing happened to my car (04 Taurus) and I had an internal regulator added to the alternator to bypass it. Sadly, there's no way to get rid of the check charging system notification that I know of.

Edited May 12, 201411 yr by Tenacious