how big of an alternator do i need?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=111766
Printed Date: June 07, 2024 at 1:44 AM

Topic: how big of an alternator do i need?

Posted By: bigrank916
Subject: how big of an alternator do i need?
Date Posted: February 19, 2009 at 11:24 PM

My truck is a 91 silverado with a stock alternator that is 80-85 amps Im told. It has a relatively new battery and electrical system has been fine. The other day on the freeway my battery led on the dash was coming on. At the time I was running the wipers, heater, stereo, and the headlights. Soon after the wipers started to shutter and slow down. I figured I was drawing too much juice with the new system and cut it off. Wouldnt you know...problem solved. My amps combined deliver about 1850 rms. I also installed some bright halogen bulbs but Im not sure if they draw any more juice than normal. So my question being with all that stuff running at the same time, how big of an alternator do I need?

Replies:

Posted By: ragsports
Date Posted: February 20, 2009 at 8:31 AM

Your amps alone are drawing over 140 amps, with this being said a 200 amp alternator should work good with this setup. Have you upgraded your big 3 yet? If not this may help your problem, but will not fix it . Start here as it will need to be done anyways when you upgrade your alt...

Posted By: bigrank916
Date Posted: February 20, 2009 at 9:37 AM

Yes I have upgraded my big three. I was thinking somewhere in the range of 175 but 200 sounds like a safer bet. Thank you for your help. Now I'll see what happens.