Alright, my lights dim when i stop at a light or just idle for a second. I thought it was my battery cause i knew it was kinda bad, so i replaced it. I bought an Optima cause you guys said it was really good. And for 100 bucks, it better be. Well anywayz, it still does it, but not as bad. But the thing is, when I floor it, the battery light comes on. This happened to me with the old battery too. Is it the UR Pullies I have? Or is it a bad alternator? anyone know what the cause of the problem may be? thankz

 

it's your alternator.....

under normal conditions your electrical system does not draw from the battery while your engine is operating. the alternator provides power for you car AND charges the battery at the same time. You battery is really only for starting you car or operating you electrical system while the engine is turned off. If your alternator goes bad, then you car will begin to draw current from the battery during driving.

if you light dims slightly during idle...i think that's normal. my car does that sometimes too, especially when my fan kicks in.

someone correct me if I'm wrong......

 

Yeah it sounds like it's your alternator. You better go get it fixed before you get stranded somewhere!!!

 

The alternator might not be bad. It might be your current draw is higher than the alternator can produce with the pullies. The battery light comes on when the voltage drops below ~11 volts. Keep reading:

Lowpost is basically right. Your alternator should provide over 14v when the car is running (my car produces 14.64v at idle). The battery doesn't do a darn thing while the car is running UNLESS the car's operationg voltage drops below the battery's standing state (most batteries will hold ~12.5v). If there is an excessive current draw (over what is being produced) - the voltage will start to drop.

If your voltage is dropping low enough to trigger the low battery warning - then either you have a seriously high current draw (like a BIG stereo, tons of neon) or something is bad (voltage regulator or alternator). If it's the first - you have no business with underdrive pullies on. If it's the second, but you do have a large current draw - then something is prob burning up b/c of the pullies as well. If your car is almost stock, then something has just worn out and needs to be replaced.

Just FYI: with our stock alternator with the stock pullies - it would take approx a 140amp continuous draw to drop the voltage to 11v. With the underdrive pullies, it would take about 125amps.

The slight dimming when the a/c or fans kick on is normal, and is a result of a short overcurrent from the start up draw.

 

damn...i better not need a alternator.....i dont have a system, or neons, or anything that would draw so much power, i never use the AC or heater....so i dont kow what could be drawing so much power. damn....dont have money to be fixing that either....i guess i just gotta keep doing what i do...idle it at 2000rpms at stop signs/lights untill i get some money. thanks for the info guys...

an other thing...the light comes on when i hit around 6200 rpms right before it shifts into 2nd. But it only happens from 1st to 2nd gear....

 

Sounds like the alternator is going. Higher RPM=more sparks in a short time=more current draw. Better fix it, else one day you might not be going anywhere.