New alternator wtf?

[Blados 10+ year member]

I installed my new 250 amp alternator today. I'm running a viper 2500d and a small component amp. The alternator IS charging but I'm still getting some pretty bad battery voltage drops and minor dimming sometimes. I did the big 3 and all that stuff. Could this voltage problem be because I'm using the stock battery or what?

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[ss3079 5,000+ posts]

What brand of alternator is it?

 

[skmfkr 5,000+ posts]

i think he got it from EA

 

[Blados 10+ year member]

bump

 

[Blados 10+ year member]

Uh oh. I hope not. I just recently bought one as well and have yet to install it.

This might be user error/normal. I'm not jumping to any conclusions. I just want some help.

 

[Renegadesrun 10+ year member]

Time to go battery shopping.

 

[Blados 10+ year member]

bump

 

[Lil Poot 5,000+ posts]

does it always happen, or only at low rpms? im assuming you've already done the big 3? i'd do it in 1/0 with such a powerful amp.

 

[Blados 10+ year member]

does it always happen, or only at low rpms? im assuming you've already done the big 3? i'd do it in 1/0 with such a powerful amp.

Mostly at low rpms... but sometimes at higher rpms. Of course the big 3 is done in 1/0. If it wasn't then my car would probably explode //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif It's just strange because it doesn't seem like it's much of an improvement from my stock alternator.

 

[Blados 10+ year member]

bump

 

[deadboi77 10+ year member]

maybe shoot an email to the person you bought it from n see what they have to say

 

[LuNaTiC 10+ year member]

2500/13.8 = 181 amps + amps needed for cars electrical = 250 amps is more than enuff, Well thats not the problem....

hrrmmm. maybe a new batt might help, not sure though.

 

[Blados 10+ year member]

Bump again. Someone smart help me out.

 

[swimfreak26 10+ year member]

Besides the diming, how can you tell the voltage is dropping? Any idea how much?

If it's only at lower rpms, or mostly, it's probably completely normal. With your alternator there should be a "birth sheet" that offers a graph to relate output to rpm. Usually they start out at idle rpm putting out substantially less than they do at driving levels. If the alt is rated 125 amps @ idle, it would explain the drops because your 2500d and an additional amp are drawing a huge amount of current.

 

[Blados 10+ year member]

Besides the diming, how can you tell the voltage is dropping? Any idea how much?
If it's only at lower rpms, or mostly, it's probably completely normal. With your alternator there should be a "birth sheet" that offers a graph to relate output to rpm. Usually they start out at idle rpm putting out substantially less than they do at driving levels. If the alt is rated 125 amps @ idle, it would explain the drops because your 2500d and an additional amp are drawing a huge amount of current.

There's a voltage meter on my dash. I can see it go down pretty far when the bass hits sometimes. I was told this one should do around 120 at idle so I understand that dimming. Unfortunately I didn't get a birth sheet or any other graph with it so I don't know exactly what to expect. Do you think a deep cycle battery would help? Are there any connections or settings or anything that could be effecting the output?