I NEED HELP

i have Alpine's MRV-F450 (5 ch amp)

If i turn it up the volume pass 1/3 with the bass cranked up sound stops. If i turn the vol down just 1 tick, 5- 10 secs latter I get sound back.

What is this?

Does the amp need that much power that the battery and alternator can't supply enough to it? I've thought about getting a 1 farad cap to see if it helps.

Also if I dont drive the car for more than 48 hrs. Next time I try to start the car I have to jump start it. If this because the amp uses alot of the battery power and doesnt have time to recover it.

Or do I just have a really bad battery.

 

Bad battery or alternator.

Try attaching jumper cables from another car and turning your volume up.

 

Here is what I did.
I wanted to drain the battery power to a point where the amp starts to turn off and then I would do your suggestion of using jumper cables.

last night i ran the amp at 3/4 9f volume (normally anything past 1/3 and sound stops from the amp) for about 1/2 hr didn't have a single issue.
Then I decided to go for a drive figure with the head lights on and foglights it would put more of a train on the power supply. About 3 blocks from the house i notice a burning smell. Thought the smell was coming from inside the car so i turned off the stereo and looked around for smoke. Didn't see anything so i kept driving to the house.
Checked the amp, it was hot but not excesively. Checked the wires around the amp they looked good checked under the hood everyhting was fine. I Ran the stereo for another few mintues still @ 3/4 of the volume. Again no issues.

Later today I'll do the volt test on the amp and foglights either one could have a ground causing the battery to die.

At this point I figure I don't need a cap since the amp ran fine @ 3/4 of the vol for 1/2 hr. I don't need it that loud for normal listening. However I do not want my battery to keep dying so I need to figure what's going there.

thanks for your help

 

Just remember something I forgot to mention earlier. On couple of occations my driver side tweeter has had no sound. I think a wire is loose.

Here's my question if a speaker wire is loose and grounding out, could this be the cause for the battery being dead (would it matter if the speaker is grouding out whilte the stereo is off).

Today when i do the volt test in about 1- 1 1/2 hr if I turn on the system and I connect the lead to each channel, the reading on each channel should be constant unless i have a short then there sould be a fluctuation right? (This way I can atleast isolate it to which channel is being grouded if it's the speaker wire at fault and not the main power wire. Dont worry the main power and ground are the first things I'm going to check.

 

I did a voltage test on the amp. I'm getting pretty good power and consistant.

While the car is off i get 12.8V, drops to 12.4 with system on.
While the car is on I get 14.6V, drops to 14.1 with system on.
the drops occur when the bass hits.

However i did find that the remote wire to the amp gets about 2.1V while the car and stereo are off. This is the reason the battery keeps dying.

Another thing I found is that every channel has different voltage running through there aren't two alike not even close.

Still don't know what is causing the amp to loose sound (power) at high volume, but I know now that it's not all the time. I ran the stereo today @ 3/4 volume again, this time for about 3 minutes only no problem (i've experience the amp loosing power @ about 1/3 the volume in the past).

 

I'll probably switch the amp from my Eclipse or MB into the Z tomorrow or Thursday (all the amps are Alpine). If I still get a Voltage reading on the remote wire I know it's faulty wiring from the head unit or EQ depending on how the shop wired the system. If I dont then the amp currently in the Z must be grounding out.

 

Hummm... where is your remote wire coming from?

 

the logical place is from the Head Unit. A shop installed the system and I wasn't there when it was being done.

 

here's the deal with the reading on the remote wire, I had my voltmeter on auto it's actually 2 milivolts so I don't think it's enough to drain the battery in 2 days.

I disconnected the power wire today and did a resistance test to see if it was grounding out. That test came back fine so it's not grounding out. After all my testing I rewired the speakers to a 2 Ohm load vs the 1 Ohm load it had. I think the amp is only stable to 2 Ohm load.

I didn't get a change to test the amp and see if changing the Ohm load fixed the no sound problem since it's kinda late and one of my neighbors is retired and the other is a cop so i dont want trouble with either.

However when I tried to start the car it wourld it (havent driven it in 3 days). The volt gage in the car read 11V, so I tested the battery and I got 11.56V. I've had cars in the past that will start on 10V.

I think I have an issue with Cold Cranking Amps and not so much Voltage. This would also explaing why the amp keeps shutting down @ high volume since the battery is the one feeding the amp and not the alternator.