I posted this in audio and I know thats where it belongs but i got no help at all so i thought I would try it in here, if the mods dont want it here, just delete it man!

I installed 2 kicker comp 12s on a fosgate 400.4 4-channell amp. As soon as re-connected the positve battery terminal(which had not come off for at least 4 months) the head unit would not turn on. After taking it back off and trying it again, it came on. Things worked fine for a few hours, then suddenly the head unit would not switch to cd function. Disconnect the terminal to reset and it fixed itself. 20 minutes later, same problem. Well reseting didnt work so I just dealt with it. Now while playing with the FIE setting on the pioneer head unit, the subs went out. I know the amp is getting power, Ive got a nice alternator whir to back that up So if the amp has power and its grounded fine and the turn on lead is connected and no fuses are blown, this tells me that the head unit is just a peice of **** and isnt sending the signal to the amp. It still wont play cds either. Its a pioneer, bout a year old maybe year and a half. Anything else it could be? I want to eliminate any other problems before I just go buy a new unit I currently cant afford. tia

OT, I know, I know...

 

Sounds like the head unit is definitely f-ed up.
If the amp is on but the subs are dead, better at least check the sub line-out to make sure the amp is getting no audio signal, otherwise the amp might be screwed too.

 

yeah there is power to the amp across the power wire, its just not turning on. It has a power lite that doesnt come on. I change radio stations and it "pops" throught the 6x9s. its like a loud click..its all kinds of f-ed up dude..

 

My Pioneer is about 7 years old now, and I had sorta the same problem it kept on turning itself off after the battery had been replaced. Turns out there is a recessed reset button somewhere on your radio, mine was behind the face plate when you flipped it down, check out your manual. Hopefully that's all that was wrong. You didn't happen to have the key turned on when you reconnected the battery did you? YOu might have fried it?

 

nope no key on..damn i would kick myself, i still think I fried it though. this weekend Im gonna hook up a new amp and test the turn-on lead by putting it on an independent switch. It just pisses me off, Ive spent a month+ building this beautiful box and gathering my parts and it thumped for like 30 hours

 

which pioneer reciever is it? cuz i know some of the newer ones and some of the older ones had this problem.

 

its a low end like $150 model, no detachable face or anything, bout a year old.

 

hmm...well then there goes my theory

 

yeah im about out of ideas as to what else it could be, and Im too cheap/stubborn to take it to a shop and let them charge me $100 to tell me what I prolly allready know

 

try this connect the amp remote to something that turns on with the car such as a cigarette lighter or something. Then the amp will not get turned off be a malfunctioning head unit. As for the head unit it does sound like it might have gotten fried or maybe the amp you have requires too much power to turn itself on and it is disrupting the power flow inside the head unit. All in all I would disconect the remote wire from the headunit and find another way to turn on the amp. Rockfords are known to require alot of milliamps of power for their turn on circuit and your head unit might not have it in it.

 

yeah that fosgate draws a lot of power, i noticed a change in idle, im upgrading the head unit tonite actually, going with a nice higher end pioneer. I isolated the turn on lead to the battery and it turned on so that solved it pretty much, thanks for all your help guys!