Problem: no power to amp suddenly

[icu400]

Ok, so here is the situation:

My amp and subs have been working fine recently, until today a series of events occurred:

1) I helped someone jump his car, and we used a red on red/black on black approach. The result was that his car works fine, and mine seems to still run normally.

2) I took my head unit out (sony 2004 model) in order to plug a cable into the aux input for my new ipod. The result was that the speakers work fine, as well as the aux ipod cable.

However, from some combination of these two events, my amp no longer turns on and the subs no longer work :/

So, to me, this means one of two things:

1) The cable that goes from the head unit to the amp to signal it to turn on is damaged.

2) The amp is receiving a signal to turn on, but not receiving power.

I notice a clicking sound when I start the car, from the amp. I took that to mean that the amp was receiving a signal from the in dash receiver. To test that, I completely disconnected the 4gauge power cable from the battery, and started the car again (with the amp receiving no power). The click still occurred. From that I am concluding that the problem is either with the amp, or with the power cable itself.


So, here is what i've looked at to see what could be wrong with the power cable. The connection with the battery seems to be secure. The fuse on the line near the battery appears intact, and the connection on both sides of it seems secure. The connection to the amp, for both ground and power, seem good. And finally, both fuses on the amp are intact as well.

This leaves me pretty stumped to be honest. The only problems i've had with the system (self install from 2004) was that sometimes corrosion on the battery would cause it to not start up right, or a few times the fuse in the engine compartment on the power cable would come loose. Nothing else ever gave me problems. The entire rest of the car stereo also works fine, the only problem is the amp.



So my question I guess is more of what should I check to fix this problem, and is it likely that the amp could have somehow broken without either of the fuses breaking in the process? Could it's power supply have just stopped working? I'm really not sure, so if anyone has any guesses on this, it would be greatly appreciated

Also, to note the specs of the system, it is a JBL amp from 2004, Infinity 10" subwoofers, and a middle line sony 2004 model head unit. I don't remember the model numbers offhand, but I could probably find them if it would be helpful information.

Thanks

 

[OMGLOLetcetc]

I had a Sony HU that had a setting to turn the RCA Preouts on and off. Maybe when you jumped the car it pulled enough power to reset the setting on your HU and now the RCA's are off. Check your HU settings.
Next, are there any power lights on the amp? Check them.
After that, take a multimeter and start checking wires.

 

[icu400]

There aren't any lights, but what I have done is wired two computer box fans to the amp, to cool it (it's covered in the enclosure). The fans have a relay that takes a signal from the same control wire that the head unit sends to the amp, to turn on, and takes power from the same cable that's connected to the amp. Since I know the head unit cable is working, and the fans aren't turning on, i'm pretty sure that it's just not getting any power.

I'm gonna try and get my hands on a meter and check the cable.

 

[Blacksheep Josh]

i'm wondering if possibly something happened when you jumped the cars off. check the fuses on the amps. they might've gone out.

 

[robtoy_r]

run a wire from the radio fuse on your fuse panel inside the car to the remote plug on your amp. or just double check to make sure the remote wire is still good from your head unit. you could have messed it up somehow when you took it out

 

[Blacksheep Josh]

i just thought of this to. i could never figure out where to hook up the remote wire in one of my older cars, until my buddy said just hook up a jumper wire from the 12v line going to the amp to the remote. and voila, the amp would work. i'm not saying you should hook this up permanently, but this should tell you if the remote wire is bad or not.

 

[robtoy_r]

well i dont know about the constant 12v because it will stay on all the time, but yes if you do it then youll know that the 12v from the battery is good and that it is the remote wire

 

[Blacksheep Josh]

well i dont know about the constant 12v because it will stay on all the time, but yes if you do it then youll know that the 12v from the battery is good and that it is the remote wire

yeah, that's what i meant. i ended up throwing a switch on it that i installed on my dash. so i could turn the subs on/off how i pleased.

but it'll let you know what's going wrong. whether it's the remote wire or the 12v from the battery.

 

[robtoy_r]

i usually pull the fuse to the radio and put the wire on there then put the fuse back in that way when the key isnt on giving power to the radio then the amp isnt on either