Amp, Subs and silly ground

[UWbeast]

Hey Everyone,

I am in the middle of installing an amp and subs in my 91 318i. Everything is going fine...almost. There is something going on with the ground connection from the amp. I tried the one dear the battery in the trunk, the metal near the battery...even the negative lead on the battery itself. It only works once in a while. I cleaned the coating of some metal near the battery tray and connected the ground there. It worked great for a few mins, then stopped again. When I connect it to most things that should work...the protect light on the amp goes out but the power doesn't come on...any ideas??

Thanks!

Steve

 

[bichmgnt]

Try pulling the negative terminal off the ground side of the battery and hooking up the amp directly to the battery. You may need to put a connection in to simulate turning the radio on. If that doesn't work I'd say you have a bad amp. I can expound if you need further info.

Steve

 

[bichmgnt]

Just reread your post. What is the protect light? It makes me think that something is being protected as if from a short and then the amp is disabled. Pulling power may reset the amp but doesn't get rid of the problem. If you hook up the amp with no inputs except for power and a possible remote turn on signal it should stay on . If it doesn't you have a problem with your amp.

Steve

 

[bignate]

Try pulling the negative terminal off the ground side of the battery and hooking up the amp directly to the battery. You may need to put a connection in to simulate turning the radio on. If that doesn't work I'd say you have a bad amp. I can expound if you need further info.

Steve

Don't do this, there is the chance that you could blow up the amp. I have both my amps grounded to the metal below the R taillight. There should already by a screw there.

 

[bichmgnt]

Are you saying there is a difference between hooking up the negative lead to some ground on the car and hooking up to the battery? There is no difference. How is he going to blow up his amp? I think he would have bigger problems if he had a bad ground. He should have the circuit fused on the positive side which I figured he already did but hooking it up across the battery directly should have no affect on whether the thing is going work or not. As a matter of fact, having a direct connection to the battery is the cleanest possible connection. If it is the only thing connected there is no interference of any kind with other systems in his car. And it doesn't depend on the battery's ground being good.

It doesn't even have to be heavy gauge wire since there will be no signal being amplified. All he's looking for is enough voltage to confirm that the amp's lights stay on. If it doesn't with the simple set up it won't when it is installed. If it does with the simple set up then he knows he needs to troubleshoot the installation.

If the protect light is coming on it may mean there is a problem with the power that may be checked by using only the battery to power the amp. The amp may need another input such as a remote turn on for the amp that would normally come from the radio. But all that is is a 12 volt signal applied to the amp as a signal to turn it on. All other inputs to the amp should be removed. This cannot blow up his amp unless he hooks it up wrong. And if he does that it won't matter where he hooks up the ground.

The only reason I can think of that the protect light might be coming on is if the amp is hooked up wrong in some way and removing all the connections and making a simple connection to the battery is the best way I can think of to test it.

The one thing you might do is try pulling all the inputs except power, ground and remote turn on and see if the symptoms change. Otherwise I'd try powering up the amp (through a fuse, of course) with nothing else connected to the battery and see if it works then. If it still doesn't work, you may need a new amp.

Just for our info what kind of amp is it? Make and model. We may be able to look up the manual on the internet and get a better idea of what might be wrong.

Steve