When I first did my install of a JL 10w3v2 and Profile 300 RMS Mono Amp, everything sounded good and was solid for a few weeks. One thing I always noticed however since the install was when I turned off the car and the stereo was on, I'd hear a thump from the subwoofer hitting 1-2 seconds after the car was off. I didn't think much of it.

Now however sometimes when listening to music, my sub will just turn off randomly. No matter how loud the music is or how soft it is. It also seems usually when I turn the car on, the sub won't turn on for about 30 seconds to a minute and then it'll hit hard until it will randomly turn off.

A friend helped me with this install and I havent had the time to look at the sub while its on and open up the trunk and see what is happening.

Can someone tell me what the problem is? Is it just a grounding problem? When I first did the install everything was fine and the sub would never shut off, but I still would get the thump after turning the car off.

Any ideas? Thanks.

D. Graphite/Graphite | Premium | Splash | Clears | Pedals | 35% TINT | Z-Tube | 4080 Stealthbox - JL 10w3 | Escort 8500 | PIAA's

 

check your ground. maybe move it to another location depending on where it is now. also how long is the ground wire? sometimes having a long ground will give u feedback. it could also be your remote wire, or even your power. make sure all connections are secure on the amp.

 

doesn't really sound like a grounding problem. since the sub amp stays on after you turn off your car for a couple of seconds and takes about 30 seconds to turn on I would look into the remote turn on wire, sounds like the installer may have picked a bad remote line. If you have a multi-meter check the voltage at the remote line with the car off, turn the car on and then turn it off. Check to see the timing of the voltage, it should go from 0v to 12v back to 0v as you turn the key. It sounds like it is turning on late and shutting off late. Most amps take a couple of seconds to turn on, this is designed to eliminate the turn on thump, but the shut off should be immediate.

When the amp shuts off during playback is it going into protection mode? There probably is a LED indicator to identify if protection mode is active. If it's going into protection it could be a short in the speaker wires since it happens at all listening levels, if it only happens at higher levels then possibly the impedance is too low for the amp.

When the amp shuts off during playback is the power LED on the amp still illuminated? If it's off check the voltage at the remote wire to see if it's still at 12v, if it's not then there's your problem.

Try to sytematically go through the troubleshooting process, starting with the remote line.

 

DHCrocks. You sound like you really know what you're talking about. I did get it checked out today by a guy that had a voltage reading and everything. He did see it was randomly coming on and the voltage seemed fine when it was on. He determined that it was a bad power cable and that he would see if he could get me one to swap it out and see if that fixed it. I will report back to see if in fact thats what it was. I wont know until he actually puts it in.

D. Graphite/Graphite | Premium | Splash | Clears | Pedals | 35% TINT | Z-Tube | 4080 Stealthbox - JL 10w3 | Escort 8500 | PIAA's

 

Check the fuse holder under the hood. A lot of the plastic ones these day are really cheap and will either not tighten properly or will heat up and melt a little, causing the fuse to make contact randomly. This can also make the 'pop' the subs after the car shuts off.



Kevin
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AIM: KPiersonTec
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Thanks Kevin. Well it seems like I have fixed the problem. The fuse may be going bad but for now I moved aroudn the terminal cable and saw the amp turning on and off. I took it off and re-crimped it and tightened it all up and this morning was hitting hard for a good solid hour with no problems. I think that was it and I know I should change the fuse sometime so that won't be a problem later on.

D. Graphite/Graphite | Premium | Splash | Clears | Pedals | 35% TINT | Z-Tube | 4080 Stealthbox - JL 10w3 | Escort 8500 | PIAA's

 

ground may have come loose