I installed a new deck and speakers all around as well as a 400 by 4 channel amp in a 91 Nissan hardbody pickup. The amp is hooked up to a set of 10 inch Sony xplode subs in a old box that had a set of Kenwood subs(one was blown). Everything worked fine but if the truck was not running the amp shutdown. Last night the guy that had the truck turned the volume up loud and the amp shut down and never came back on. I went over all wiring and fuses the light on the amp comes on (red)so I am sure it is wired right. I never got sound . Am I missing something or is this amp toast?Please help . Still do not know why it kept shutting down I wonder if the alternator is not pushing enough Juice. He wants to buy a1000 watt amp and use that to push the subs and then use the 400 to push the rest of the speakers. I am not sure this is the best choice for him as he had a shutdown problem with a 400 watt amp.
Replies (12)
ttocs on 07/29/2003 22:10:34
I would take a close look at your pwr wiring. If it was shutting down only when the truck was off it sounds like you have a bad connection somewhere. What size wire do you have running to the amp? If you are not for sure, if you look at the wire it is normally written very small every foot or so(8 awg). Where is the amp grounded at and how(factory bolt, screw, ect)? Do you have access to a multi meter..
baine on 07/29/2003 22:35:10
I used A 8 guage power / ground the power wire is a fused link. The ground is on the seat mounting bolt. I figure that if the amp power is on the the power ground and amp turn on are all working then the wiring is fine.... Right? the Problem is now the amp is shut down ( no sound) but the power light is on. I turned the gain all the way down and disconnected all of the wires to the amp . then reconnected them and still the light is on(red) but no sound . Some amps have a protection mode that will kill the amp and the light goes from green to red. This is not my amp so I do not know if this is the case. If it is dose any one know the trick to resetting said function. No i do not have access to a multi meter
Swez on 07/31/2003 21:50:28
May have overlaoded this amp with too low an ohms load. When we do this the amp will shut down or go into protect mode.
Some amps have internal resets that can be done by factory authorized Tech. But since the amp power light dose come on you may have some power going to the amp, but if that ground is not fully functioning (poor ground) power will not be adequate to fire the amp into full action mode.
Audiobhan is one amp that will behave like this and has to be reset by factory tech.
Finally, the power supply may still be good but the output transistors may be fried. Red lights on an amp usually indicate protect mode while green is all is OK.
Swez
baine on 08/2/2003 00:25:17
The messed up thing is it came back on after two days of being shutdown, then went down in about 30 min and was too hot to touch. The ground is a seat bolt w/ carpet under it I am thinking mabey a diff ground loc. He took the amp back (i think) to walmart ( yea a cheap amp) and is going to get a nother one. ( I told him to buy better stuff but he does not want to dump cash In something that is rated the same watts x channel. Could the ground really be the prob I figured it was getting power so it works. Also any Ideas for a good amp that is not pricy
ttocs on 08/2/2003 00:43:04
of there is carpet under the amp ground, then you need to chng that......... Next thing is you need to test the input. Get a walkman/diskman/whatever with a headphone to rca conn. Plug them into the amp with the deck on, and see if you get sound out. If you get the speakers to work, then the input you disconnected(deck) is bad...
baine on 08/2/2003 01:00:36
Ok let me get this you want me to plug headphones in the amP or the back of the deck. a little confused
baine on 08/2/2003 01:09:23
ohh i got it you want me to plug the rca out of the HU in the the walkman and see if i get sound....:-)
SkinRock on 08/2/2003 14:05:09
First off, you said that the amp was too hot to touch, that is a sign of too low of a load to the amp. If you go below the minimum load, the amp will shut itself off, and usually generates a lot of heat. Also, www.etronics.com has a lot of good deals on car audio. I just bought a pair of Sony P5 12 subs from BestBuy, which cost me 150 bucks on sale, at that site, they run 100 bucks a pair. I decided to buy my new amp from them because of this, I got the Sony P5 800 watt Class D Mono Block. Retail: $250. What I paid: $150. By the way, that amp pounds. :-)
Swez on 08/2/2003 14:25:39
If you can take the amp back and try another. The amp (as Blain said) is overheating due to poor match of speaker load to the amp. It is shutting down to protect itself from thermal destuction.
Sony makes mostly Single voice coil, 4 ohm subs. If you wire them in parallel to each other and run them off a a bridged amp, 2 ohms is too low and the amp will react by overheating.
The safest way to wire your subs to a 2/4 channel amp, if to bridge the amp into 3 channels and run 1 sub per channel... 4 ohms laod to each channel and set your gains at midpoint or so on the amp.
As for grounding, the seat bolt is not a bad place to ground... but you need bare metal to make full contact with body grounded electricals. That means sanding all the paint, rust etc., then installing the ground wire. A dab of silicone will keep rust problems from developing as well.
Swez
baine on 08/2/2003 15:55:18
Ok I am running a 4channel 400watt amp each side is briged it names it front and rear so I have the rear bridged and the front is bridged .That should give me about 200watts per sub. I think this is a four ohm load. It is a cheap amp and It did run fine with the speakers it had in it. One side was blown so i gave him a old RF series 1 sub that the surround needed glued but it still sounded fine. He wanted to get something that matched and looked good. Now I am not sure if the old subs were 8ohm or 4ohm. The new subs are 4ohm and the amp even said bridgeable on the box. Once we installed the new subs the amp started shutting down. Now this box is one of the old kenwood boxes with a small mid and a tweeter on each side with a built in crossover . Now I am not sure,Could the old box been made to a 8 ohm spec and that is why the amp crashes??? Is there a solution for the prob if thats the case IE unhooking the crosseover and mid and tweeters. Now he wants to buy a cheap leagacy 1200 watt amp to run the subs , and use the new amp( the one walmart gave him for the old one ) to push the speakers that are in the factory mounts.
baine on 08/2/2003 20:03:34
OK heres the deal now. new amp and same prob so dose that mean the pre amp outs on the HUare toast?????or is there something else it could be
baine on 08/2/2003 21:30:07
could the speakers be blown or the xover on the sub box be blown the xover is just a small board by each terminal in the sub box it is wired to the tweets
Replies (12)
ttocs on 07/29/2003 22:10:34
I would take a close look at your pwr wiring. If it was shutting down only when the truck was off it sounds like you have a bad connection somewhere. What size wire do you have running to the amp? If you are not for sure, if you look at the wire it is normally written very small every foot or so(8 awg). Where is the amp grounded at and how(factory bolt, screw, ect)? Do you have access to a multi meter..
baine on 07/29/2003 22:35:10
I used A 8 guage power / ground the power wire is a fused link. The ground is on the seat mounting bolt. I figure that if the amp power is on the the power ground and amp turn on are all working then the wiring is fine.... Right? the Problem is now the amp is shut down ( no sound) but the power light is on. I turned the gain all the way down and disconnected all of the wires to the amp . then reconnected them and still the light is on(red) but no sound . Some amps have a protection mode that will kill the amp and the light goes from green to red. This is not my amp so I do not know if this is the case. If it is dose any one know the trick to resetting said function. No i do not have access to a multi meter
Swez on 07/31/2003 21:50:28
May have overlaoded this amp with too low an ohms load. When we do this the amp will shut down or go into protect mode.
Some amps have internal resets that can be done by factory authorized Tech. But since the amp power light dose come on you may have some power going to the amp, but if that ground is not fully functioning (poor ground) power will not be adequate to fire the amp into full action mode.
Audiobhan is one amp that will behave like this and has to be reset by factory tech.
Finally, the power supply may still be good but the output transistors may be fried. Red lights on an amp usually indicate protect mode while green is all is OK.
Swez
baine on 08/2/2003 00:25:17
The messed up thing is it came back on after two days of being shutdown, then went down in about 30 min and was too hot to touch. The ground is a seat bolt w/ carpet under it I am thinking mabey a diff ground loc. He took the amp back (i think) to walmart ( yea a cheap amp) and is going to get a nother one. ( I told him to buy better stuff but he does not want to dump cash In something that is rated the same watts x channel. Could the ground really be the prob I figured it was getting power so it works. Also any Ideas for a good amp that is not pricy
ttocs on 08/2/2003 00:43:04
of there is carpet under the amp ground, then you need to chng that......... Next thing is you need to test the input. Get a walkman/diskman/whatever with a headphone to rca conn. Plug them into the amp with the deck on, and see if you get sound out. If you get the speakers to work, then the input you disconnected(deck) is bad...
baine on 08/2/2003 01:00:36
Ok let me get this you want me to plug headphones in the amP or the back of the deck. a little confused
baine on 08/2/2003 01:09:23
ohh i got it you want me to plug the rca out of the HU in the the walkman and see if i get sound....:-)
SkinRock on 08/2/2003 14:05:09
First off, you said that the amp was too hot to touch, that is a sign of too low of a load to the amp. If you go below the minimum load, the amp will shut itself off, and usually generates a lot of heat. Also, www.etronics.com has a lot of good deals on car audio. I just bought a pair of Sony P5 12 subs from BestBuy, which cost me 150 bucks on sale, at that site, they run 100 bucks a pair. I decided to buy my new amp from them because of this, I got the Sony P5 800 watt Class D Mono Block. Retail: $250. What I paid: $150. By the way, that amp pounds. :-)
Swez on 08/2/2003 14:25:39
If you can take the amp back and try another. The amp (as Blain said) is overheating due to poor match of speaker load to the amp. It is shutting down to protect itself from thermal destuction.
Sony makes mostly Single voice coil, 4 ohm subs. If you wire them in parallel to each other and run them off a a bridged amp, 2 ohms is too low and the amp will react by overheating.
The safest way to wire your subs to a 2/4 channel amp, if to bridge the amp into 3 channels and run 1 sub per channel... 4 ohms laod to each channel and set your gains at midpoint or so on the amp.
As for grounding, the seat bolt is not a bad place to ground... but you need bare metal to make full contact with body grounded electricals. That means sanding all the paint, rust etc., then installing the ground wire. A dab of silicone will keep rust problems from developing as well.
Swez
baine on 08/2/2003 15:55:18
Ok I am running a 4channel 400watt amp each side is briged it names it front and rear so I have the rear bridged and the front is bridged .That should give me about 200watts per sub. I think this is a four ohm load. It is a cheap amp and It did run fine with the speakers it had in it. One side was blown so i gave him a old RF series 1 sub that the surround needed glued but it still sounded fine. He wanted to get something that matched and looked good. Now I am not sure if the old subs were 8ohm or 4ohm. The new subs are 4ohm and the amp even said bridgeable on the box. Once we installed the new subs the amp started shutting down. Now this box is one of the old kenwood boxes with a small mid and a tweeter on each side with a built in crossover . Now I am not sure,Could the old box been made to a 8 ohm spec and that is why the amp crashes??? Is there a solution for the prob if thats the case IE unhooking the crosseover and mid and tweeters. Now he wants to buy a cheap leagacy 1200 watt amp to run the subs , and use the new amp( the one walmart gave him for the old one ) to push the speakers that are in the factory mounts.
baine on 08/2/2003 20:03:34
OK heres the deal now. new amp and same prob so dose that mean the pre amp outs on the HUare toast?????or is there something else it could be
baine on 08/2/2003 21:30:07
could the speakers be blown or the xover on the sub box be blown the xover is just a small board by each terminal in the sub box it is wired to the tweets
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