voltage drop at amp
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=122811
Printed Date: May 14, 2024 at 4:58 PM
Topic: voltage drop at amp
Posted By: mr_joker777
Subject: voltage drop at amp
Date Posted: July 24, 2010 at 11:06 AM
Hello,
I just started having a problem with my wiring for my amp. I changed my fuse holder from the plastic blade type to the glass tube style. The plastic one was getting very hot and melted a little I was having a problem with voltage drop after it did melt a little and my amp went into protection. I have a 07 chrysler 300 and the battery is in the trunk so the power wire is roughly 4ft long. When I check the voltage when running at the battery it is 14v, the fuse also 14v, the end of the wire it is 14v. As soon as I hook it up to the amp it reads 8v at the fuse and the amp. This is driving me crazy. The amp is a kicker 400.1 and the subs are kicker c15 4-ohm single voice coils wired to 2-ohm. If anyone knows why I'm getting this drop please help. I am going to try the amp in a friends car in the next couple days see if it does a similar drop in his system or not.
Replies:
Posted By: i am an idiot
Date Posted: July 24, 2010 at 1:35 PM
You have a defective fuse or a bad connection at the fuse holder. If it is an AGU type fuse, chances are it is the fuse itself.
Posted By: tommy...
Date Posted: July 24, 2010 at 2:48 PM
Yeah you will get some crazy readings , listen to that guy...........................^
-------------
M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!
Posted By: oldspark
Date Posted: July 24, 2010 at 9:08 PM
Is the input of the fuse also well under 14V? (Or only after the fuse?)
If your amp is 400W RMS it probably means at least a 40A fuse which is the largest ATS (normal sized) blade fuse, though generally in-line wire blade fuse-holders are not rated above 30A.
I'd suggest the distribution is generally too light - especially if the input to the fuse (which should be close to the battery) had a voltage drop from the battery.
As that Idiot and his fan Tommy seem to suggest, glass fuses are notorious for bad connections and voltage drops (too many conductive joints) - one-piece like blade, Maxi, ANL etc are MUCH better and reliable. (Else circuit breakers from a cost POV if fuses constantly blow for reasons that cannot be eliminated.)
But measuring voltage at different points - or the voltage drop between different points along the distribution (across the fuse, from battery to fuse, etc) will show the worst drops. Upgrade cabling etc to minimise drops.
And don't forget the ground path(s)!
|