Im not trying to be rude to you at all.
But like Perry and others have said it could be your battery.
For example theres no amp in the car and it starts fine.
You put the amp in the car it doesnt start.
Think for a min here
The battery has to supply voltage and amprege to the starter of the car and the lights in the dash that come on and supply power else where that needs it to start the car.
So now you add an amp which takes even more voltage away from the battery
In return so many things need power from that battery it could be falling on its face when everything is connected.
So your battery may have a dead cell in it and just cant keep up with all the stuff that connected to it.
Like i said you should drive down to a parts store and have the battery checked out to see if it passes the load test.
Automotive store usually load test the battery for free of charge .
So if the battery tests fine what are you out besides a few mins of your time.
If you open the amp up and start testing stuff theres more time involved on checking things in the amp then what it would take to get the battery checked.
Also you say its the amp and you decide not to mess with it yourself.
So you send it out to someone for repair. They find out theres nothing wrong with the amp now your out shipping costs there and back.
So would you rather be out alot of time or even money when you can be 100% sure if its the battery or not by taking time to go get the battery tested free of charge
But like Perry and others have said it could be your battery.
For example theres no amp in the car and it starts fine.
You put the amp in the car it doesnt start.
Think for a min here
The battery has to supply voltage and amprege to the starter of the car and the lights in the dash that come on and supply power else where that needs it to start the car.
So now you add an amp which takes even more voltage away from the battery
In return so many things need power from that battery it could be falling on its face when everything is connected.
So your battery may have a dead cell in it and just cant keep up with all the stuff that connected to it.
Like i said you should drive down to a parts store and have the battery checked out to see if it passes the load test.
Automotive store usually load test the battery for free of charge .
So if the battery tests fine what are you out besides a few mins of your time.
If you open the amp up and start testing stuff theres more time involved on checking things in the amp then what it would take to get the battery checked.
Also you say its the amp and you decide not to mess with it yourself.
So you send it out to someone for repair. They find out theres nothing wrong with the amp now your out shipping costs there and back.
So would you rather be out alot of time or even money when you can be 100% sure if its the battery or not by taking time to go get the battery tested free of charge
Well, I'm not trying to be rude either, but I fail to understand why everyone is yapping about the battery so much when it is obvious his amp is messed up.
Regardless if the amp sometimes plays or 30 amps or 9 volts blah blah, what he is describing is NOT normal for a car stereo amp. And he didn't mention ANY problems starting the car until he connected his amp backwards and it pretty certainly seems damaged it.
--> Fix the amp or throw it out!!!
Meanwhile, it's possible all this goofing around has indeed damaged the battery, so:
- Stop connecting the amp to the car before you possibly damage other vehicle electronics.
- I agree, do load test your battery to see if you've damaged it irretrievably
PS: If the ohmmeter trends down towards zero, that's not capacitors charging, that should start out reading zero and then drift up towards infinity. Er, that test should be with the amp NOT connected-was it? Anyway, doesn't matter, something about the amp is blown.
Regardless if the amp sometimes plays or 30 amps or 9 volts blah blah, what he is describing is NOT normal for a car stereo amp. And he didn't mention ANY problems starting the car until he connected his amp backwards and it pretty certainly seems damaged it.
--> Fix the amp or throw it out!!!
Meanwhile, it's possible all this goofing around has indeed damaged the battery, so:
- Stop connecting the amp to the car before you possibly damage other vehicle electronics.
- I agree, do load test your battery to see if you've damaged it irretrievably
PS: If the ohmmeter trends down towards zero, that's not capacitors charging, that should start out reading zero and then drift up towards infinity. Er, that test should be with the amp NOT connected-was it? Anyway, doesn't matter, something about the amp is blown.
The attached image shows a battery being tested with an intermittent load of 200 amps. Notice that the voltage never drops below 11 volts. The second image is at 450 amps. It still holds above 9v. If he has a 30 amp fuse (which could not possibly pass nearly 200 amps without blowing), there's no way to drag the battery voltage down to 9v via a 30 amp fuse unless the battery is defective. A battery with a shorted cell can produce enough current to start the vehicle but it won't have any capacity to produce and hold anything near 12v.
The meter may count up or down depending on whether the capacitors were being charged by the ohm meter or being discharged by the meter. A short would not produce a varying voltage. It would go to and remain at 0v or 0 ohms (depending on whether the meter was set to diode check or ohms).
The meter may count up or down depending on whether the capacitors were being charged by the ohm meter or being discharged by the meter. A short would not produce a varying voltage. It would go to and remain at 0v or 0 ohms (depending on whether the meter was set to diode check or ohms).
Attachments
Ah, good point.
As for the rest, I can only imagine he's damaged something such that the amp works but is somehow bleeding let's say 29 amps continuous. The fuse doesn't blow, but discharges the battery really hard. (Especially if the battery was damaged by the previous foolings around, or as Perry put it "defective").
So it still seems to me:
- Amp need repair
- Battery needs load test, and maybe replace
Where are you connecting this amp? You stated that you connected it directly to the battery and it works fine so where are you connecting it otherwise??? It should only be connected to the battery, not a fuse box and not any other power soure in the car.
Are you using the turn on lead or did you just hot wire it to B+? Is your power wire at least 10 ga. For 30 amp circuit?
Did you also upgrade the ground wire back to the battery and car body/frame? That also needs to be sufficient to carry the load as the B+ lead.
When it kills the battery during engine off play, how long does it play before the battery dies?
How long are you playing it when it gets warm and how warm? Too hot to touch? Warm is normal, egg frying is not.
Are your speaker baskets isolated from the car's body or are the baskets in direct contact with the metal of the car?
Are you using the stock car wiring for the speakers or did you run new? If using the stock wiring, did you verify that it is floating and not common ground?
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ok to answer yur questions:
1) i the only ting i changed was the ground....instead of groundin on d body i ground on battery.......wen it was grounded on battery the car started normal...but grounded on body it wasnt.
2) i am using the turn on lead and yes am usin a 10ga for the power
3) when engine off it can play 4 bout 15-30mins
4) its nut burning up hott but it getts hott cudd still put hand on it for a little wile( if i install another fan on the back will this help)
5) yes the speakers are isolated from the body and i changes the wiring to the speakers...to a thicker wire
1) i the only ting i changed was the ground....instead of groundin on d body i ground on battery.......wen it was grounded on battery the car started normal...but grounded on body it wasnt.
2) i am using the turn on lead and yes am usin a 10ga for the power
3) when engine off it can play 4 bout 15-30mins
4) its nut burning up hott but it getts hott cudd still put hand on it for a little wile( if i install another fan on the back will this help)
5) yes the speakers are isolated from the body and i changes the wiring to the speakers...to a thicker wire
Well it stands to reason that you have a grounding problem with your car. Make sure the grounds from the battery to the body and frame and battery to engine to frame are all intact. At the point where you connected the ground (not the battery) did you scrape off the paint from the surface or ensure that it is actually a grounded point? The seat bolt works well for grounding the amp.
Always ground close to the amp and not another run to the battery. This will reduce the potential for a ground loop and induce noise into the system. Also, make sure that the ground path is sufficient to carry the extra load. The B+ is only 50% of the circuit, the other 50% is the return through the body and ground wiring. It all must be sufficient.
30 min. of off engine run time is not really short if you are cranking it. If you want engine off run time then you need to install another battery for longer run time or connect a power supply during that time.
As said before, install a fuse on the B+ wire within 18" of the battery so if there is a short, it doesn't burn the wire under the carpet like dynamite fuse and start a fire. This fuse is to protect the wire, not the amp.
Always ground close to the amp and not another run to the battery. This will reduce the potential for a ground loop and induce noise into the system. Also, make sure that the ground path is sufficient to carry the extra load. The B+ is only 50% of the circuit, the other 50% is the return through the body and ground wiring. It all must be sufficient.
30 min. of off engine run time is not really short if you are cranking it. If you want engine off run time then you need to install another battery for longer run time or connect a power supply during that time.
As said before, install a fuse on the B+ wire within 18" of the battery so if there is a short, it doesn't burn the wire under the carpet like dynamite fuse and start a fire. This fuse is to protect the wire, not the amp.
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