Hey everyone...

I've been having problems with my system lately. Specifically, it LOOKS like the amp I've been using to drive my subwoofer may be dead... or just mostly dead. I don't know, which is why I'm asking here.

Here's what I've got for my system:

Alpine CDA-7995 head unit
which feeds 2 amps:

JL Audio 300/4
JL Audio 500/1

2 channels of the 300/4 feed a pair of MB Quart QSD-210's, and the other 2 channels feed a MB Quart QSD-164 midbass add-on kit (which gives me a 6"/4"/1" 3-way system.) I'm not running any rears.

The 500/1 runs a JL Audio 10W6v2 sub which sits in the center well of my trunk.

Now I've noticed for awhile that the sub is out, so I went ahead and started looking at things. I first checked the fuses... the fuse that feeds my 500/1 was blown. Okay, no biggie. So I plop another fuse in there... yet it sparks when I put it in there (The stereo was definitely off when I replaced the fuse!). So I get out my multimeter. With the stereo off, the amp was drawing 10A of power... WITH THE STEREO OFF!. I double-checked the voltages at the amp terminals. 12V across the + and - terminals, and 0V at the remote-turn-on port (with the stereo turned off, like I would expect it). Same for the 300/4 (as expected).

So... do I have a blown amp? Or how do I determine this conclusively?

I had the whole system installed at a Hi-Fi Buys (aka Tweeter) in central Georgia (and even paid for the 5-yr warranty on everything), but damned if Tweeter didn't just close up their shops here in Dallas. Which means if I need to have the amp replaced under warranty, I'd need to take it all the way to Houston. In all honesty I've not been 100% satisfied with their install -- they DIDN'T use a grommet or sealant to seal the hole they drilled in my firewall, and with the thunder-boomer drenching storms we get here in TX, that resulted in a VERY wet passenger footwell, which introduced ANOTHER slew of problems... Plus they actually DRILLED a hole in the body right behind the passenger seat to run the ground cables... when I told the sales/install manager that they could AND SHOULD just run the ground cable to the bolt on the passenger seat which is a chassis ground anyways.

Argh.

So anyhow... any input/suggestions would be welcome.

 

It sure sounds like there's an electrical problem. Your amp isn't necessarily blown, but the electronics driving the on/off certainly are having a problem.

You might want to call the Tweeter in Houston and maybe fax the manager your receipt, warranty info, etc. You may be able to pull the amp yourself and UPS it to them to have it taken care of and save yourself the travel time.

Shame about the install, that is darned shoddy workmanship.

 

also check to see if the cable that goes through the firewall is cut or damaged.

 

I checked the cable through the firewall, that's fine. Basically the main power cable (4ga) comes back to a fused distribution block where it splits into 2x 8ga cables.