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Amp/sub questions. Any audio experts here?

1K views 14 replies 9 participants last post by  ChasUGC 
#1 ·
So I have a new system, fairly large, but I got it for cheap. 2 kicker 12in comp s and a kicker amplifier with 4g wiring. Have everything hooked up, but when I go to plug the battery cables back on...it blows the 80amp AFS fuse in the glass tube in the power wire. Now this is a new set, never used before. Why would this fuse be blowing over and over? The power wire is not damaged, the ground wire has a clean connection and the speakers work fine(so there is no short there) any ideas? Hopefully someone can help! Thanks guys
 
#3 ·
It sounds like your positive and negative lines are backwards at some point. Or you have a poor ground. Where is your amp grounded? It should be ground no more that 18 inches away from the amp is located. Be sure your ground is direct to steel (chassis) and not to any kind of aluminum. And make sure the ground is tight, very tight. A loose ground can cause arcing which cause the device to draw an insane amount of current which will blow your fuse. If your positive and negative lines are crossed or miswired the same result can also be achieved.
 
#8 ·
Let me move this to the electronics thread.

This is the JK general section, and it looks like you are not even talking about a JK.
 
#9 ·
New to forum and Jeep Wranglers. Just bought "new to me" 2000 TJ Sport a few weeks ago and am loving it so far. Anyways, felt the need to chime in due to the nature of the request. I am an Electrical Engineer for a Japanese Consumer Electronics company here in SW Ohio. 15 years experience designing aftermarket and OEM amps and radios. From my experience, about the only thing that will blow 80A or 100A fuses like that is a direct short to GND from +B line. Could be a short within the amp....short in one/some of the amp's output FET's or in the wiring on the 4AWG line somewhere. Or hate bringing it up, but people do it all the time.....reverse the +B and GND lines somewhere. Most amps have a built in reverse battery protection diode that will immediately blow the fuse if for whatever reason the customer gets the +B and GND lines swapped upon installation. Is amp brand new or used? Could be an issue with it if used.
 
#10 ·
New to forum and Jeep Wranglers. Just bought "new to me" 2000 TJ Sport a few weeks ago and am loving it so far. Anyways, felt the need to chime in due to the nature of the request. I am an Electrical Engineer for Japanese Consumer Electronics company here in SW Ohio. 15 years experience designing aftermarket and OEM amps and radios. From my experience, about the only thing that will blow 80A or 100A fuses like that is a direct short to GND from +B line. Could be a short within the amp....short in one/some of the amp's output FET's or in the wiring on the 4AWG line somewhere. Or hate bringing it up, but people do it all the time.....reverse the +B and GND lines somewhere. Most amps have a built in reverse battery protection diode that will immediately blow the fuse if for whatever reason the customer gets the +B and GND lines swapped upon installation. Is amp brand new or used? Could be an issue with it if used.
thanks for helping me! It's brand new from crutchfield
 
#12 ·
I would use a process of elimination.

Obviously something is drawing a lot of current to blow the fuse.

Disconnect the power cable from the amplifier and attach the battery cables. If the fuse still blows, it is not the amp. If it doesn't, the amp is the problem.

Repeat this process with everything connected to the power leads until you find the problem device.
 
#13 ·
What head unit are you hooking to the amp? This is what I would do. Disconnect all speaker wiring except for the amp ground, power 12v, power antenna and RCA jacks.Turn radio on and if it doesn't blow, hook up speakers to test each amp speaker output. Is it a bridgeable amp and how are your subs connected to it? If it blows an 80amp fuse(never seen an amp use that big of a fuse), NEVER put in a larger fuse. Also keep your ground short and to clean metal.
 
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