How many amp fuse to use?

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=21876
Printed Date: July 15, 2025 at 5:52 AM

Topic: How many amp fuse to use?

Posted By: bassam_zaman
Subject: How many amp fuse to use?
Date Posted: November 24, 2003 at 6:39 AM

im purchasing an mtx 801D amp (800watts x1 one at 2 ohm) . It has three 25amp fuses on the unit and im gonna purcahse 4 gauge wire and i need to know how many amps the fuse on the power wire should be. I checked on the website it says somthing like 100 amps fro 800 watts. But i think thats to high and it could cause some damage. Plz help me out! thnaks.

Replies:

Posted By: mobiletoys2002
Date Posted: November 24, 2003 at 9:43 AM

Your current draw at the full power of 800 watts would be about 64 amps so you can try a 60 amp fuse and if it dont blow at high levels that fuse will be fine.

Posted By: Stevolon
Date Posted: November 24, 2003 at 9:46 AM

hi bassam_zaman,

The fuse under the hood is not to protect anything but a short to the body of your car. You want to pick a fuse that will not blow from the current draw of your amp or amps. Trust me you could use a 200 amp fuse and if you were in an accident and your power wire got pinched to ground, the fuse is going to blow.... I would think that for your power requirements a 100 or even an 80 amp fuse would work just fine. Remember this fuse is to protect from fire under your hood and should be as close to the power supply as possible (18" or less).

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Steve@A.E.S