Mach 460 Amps bad?

ForeverDriven

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Hey everyone, quick question and description of my issue.

Ever since I got this car (a 97 GT with the Mach 460) there has been little to no bass and significant "radio buzz" that follows the volume. What I've found is that my front speakers and all tweeters work fine, even the tweeters in the back (with the amps unplugged).

With the tweeters so close, and so little headroom, I'm not too sure if there is any sound coming from the subwoofers at all, but the best bet is probably not. The amp's front black plug (6 pin, only 3 connected tho) has power. A ground, a 12V, and a 5V like it should be, so there is no main power issue.

The headunit is some old Pioneer crap, not too concerned about this right now.

So if my issues persist (the radio buzz and no bass) even after both amps are unplugged and removed, do you think this is another case of Mach 460 amps just dying out, or do you think the speakers may be at fault? Or do you think no bass and the buzz are separate issues? I just assume the electrical signal is getting buzzed by the faulty bass in the system. Any input appreciated.

Thanks!
 

ttocs

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the rear amps are just for the woofers front and rear. The tweeter amp is actually under the radio. So with both amps in the back disconnected you should have no bass. With them plugged in you should have some bass although depending on how they wired in its probably weak at best. If you do not notice anything with the amps plugged in go check all the fuses in the fusebox to be sure its not that simple.
 

ForeverDriven

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the rear amps are just for the woofers front and rear. The tweeter amp is actually under the radio. So with both amps in the back disconnected you should have no bass. With them plugged in you should have some bass although depending on how they wired in its probably weak at best. If you do not notice anything with the amps plugged in go check all the fuses in the fusebox to be sure its not that simple.
The amps have power to them, so I'd assume there aren't any fuse problems. Not that I have any blown fuses anyway
 

ttocs

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ok so then we need to figure out if they have signal. To do that I need to know how the deck was wired into the stock wiring as there is a couple of ways. If you can pull the radio out and get a pic of the wiring going to it I will know what they did.
 

ForeverDriven

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ok so then we need to figure out if they have signal. To do that I need to know how the deck was wired into the stock wiring as there is a couple of ways. If you can pull the radio out and get a pic of the wiring going to it I will know what they did.
Here are two photos. So actually, when I went to replug in that big black cable (and I reconnected the amps too) nothing turned on . Maybe pulled that blue wire off of a connector. Will keep looking, but as of right now the whole system just stopped working, even with black cable and amps disconnected again
 

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ttocs

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I need to see the harnesses on the other end of those wires that plugs into the factory wiring. The speakers specifically will either go to a small square plug(maybe 1" square) or to a larger rectangular harness(3"x 1" or so). I am willing to bet it goes to the smaller one but I need to be sure.
 

ttocs

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and insulate that orange/white wires end with a piece of tape or something you do not want that to ground out.
 

Flade

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The Mach 460 sometimes has a grounding issue causing a buzz. The problem occurs at the cable connector behind the drivers kick panel. Take off the kick panel, seperate the connector, clean the connections, add some dielectric grease and put it back together. Put a tie wrap around it to keep it tightly together and put the kick panel back on.
 

ForeverDriven

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I need to see the harnesses on the other end of those wires that plugs into the factory wiring. The speakers specifically will either go to a small square plug(maybe 1" square) or to a larger rectangular harness(3"x 1" or so). I am willing to bet it goes to the smaller one but I need to be sure.
So I noticed what you mean by the square plug or the rectangular plug. It actually goes to both..? Mostly to the square plug and a few to the rectangular one (like the blue wire that was pulled out and the two orange wires)
 

ttocs

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unplug the larger rectangular harness and then see if you hear any bass from the woofers, assuming the amps are all plugged in.
 

ForeverDriven

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The Mach 460 sometimes has a grounding issue causing a buzz. The problem occurs at the cable connector behind the drivers kick panel. Take off the kick panel, seperate the connector, clean the connections, add some dielectric grease and put it back together. Put a tie wrap around it to keep it tightly together and put the kick panel back on.
Also heard of this. Will also check it out
 

yankytuna

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The amps have power to them, so I'd assume there aren't any fuse problems. Not that I have any blown fuses anyway
I have a 95 with the 460 system. The took out the 460 head unit and replaced it with a pioneer. Nothing worked. I reinstalled a a 460 head unit with the proper wire harness and I get volume, bass and no noise.
 

ttocs

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I have a 95 with the 460 system. The took out the 460 head unit and replaced it with a pioneer. Nothing worked. I reinstalled a a 460 head unit with the proper wire harness and I get volume, bass and no noise.
start a post about it and we/I can get ya jammin again.
 

ForeverDriven

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Hey guys, back from that short break lol.

After looking at how awfully the old head unit was wired, I decided to just get a brand new unit with the Metra 70-5510 harness. I am 100% confident it is now wired properly at the head unit.

Good news? No buzz.

Bad news? Still no bass.

The system sounds the same no matter if both, only one, or neither rear amps are plugged in. Touch the front amp though, and it won't work no matter the plug, so that must still be working.

Another small note is that the bottom door panel speakers are not sending out any audio at all. It is hard for me to tell if the larger rear speakers are working but the front and rear tweeters definitely are (I don't know what the smaller rear speakers are, forgive me if thats incorrect). Again, none of this changes no matter how you have the rear amps plugged in.

Amps are 100% getting power from the 3 pin connectors. 5 volt turn on, 12-volt power, ground. Am not sure how to test the amp's other plugs for any deficiencies, can't find diagrams.

Also, that connector in the driver-side kick panel was good and secure.

Looks like I just might either take it to an audio shop or at least have Best Buy test the amps out, see if they work at all.
 

ttocs

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if you have confirmed power at the amps and everything is plugged in the only way to really test if the amp is bad is to swap it out and see what happens.
 

ForeverDriven

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if you have confirmed power at the amps and everything is plugged in the only way to really test if the amp is bad is to swap it out and see what happens.
Honestly yeah, will have to see.

Am going to take the amp's casing off tho to look for any burns or bad capacitors
 

ttocs

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at this point unless you are dead set on keeping everything stock I would say to look to the aftermarket. You can fit a nice component set up front and with a pair of coax 5 x 7s in the back and a nice sub you will be just as happy and with less problems later on.
 

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