Mach460 only bass working

KCSAse98gt

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New to forum and I've been searching for someone with the same issue but haven't found one. I just got my high school car back after passing it on to my niece, a 1998 mustang gt. I was pretty excited to get it back but was disappointed to see she had pulled the factory head unit and replaced it with a $30 generic hu. Also they used the wrong wiring kit bypassing the amps. So all that was working were the tweeters with no bass at all.
I purchased the correct wire harness, a sony double din hu, and double din conversion kit. After installation only one of the back subs was working. I then purchased a new front amp and one rear amp. After installing the rear amp both back subs are now working. Changing the front amp did nothing. I can't get any of the tweeters or front subs to work. I think the front subs may just be blown though but I know the tweeters work, as that is all that was working before. I took a voltmeter and checked connections and measured the expected voltages. At a loss on what to do, I went to a car audio store and paid $125 for them to troubleshoot and they couldn't figure it out either. I was then quoted $2500 for them to install a new system. Has anyone had a similar issue, all I can find are no bass issues but I have the opposite issue. Only bass and no highs. Any help would be appreciated.
 

ttocs

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have we checked fuses? Can you get a pic of how you wired into it? There are a few different ways and if we can see it we will be a step ahead.
 
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KCSAse98gt

KCSAse98gt

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I have checked all fuses. This is the current setup. I also tried it with the RC cables style going into the amp connector but switched to this style to see if it would make a difference, it did not. I've also removed the solid blue wire (power antenna) from the blue white connection (amp turn on) which also didn't help. Last picture are all the unused connectors I have.20200224_170152.jpg 20200224_170240.jpg 20200224_170215.jpg 20200224_165830.jpg 20200224_170904.jpg
 

ttocs

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lets start simple. In the last pic directly above there are a number of unused harnesses which is normal. If you look at them you will see two thick black wires that are the only two to only have one wire connection. Those are grounds, one was for the deck and I am pretty sure the other went to the amp. Try grounding both of those and see if you get sound from it. All you need to connect is a simple male spade connector but to do a quick test you can just strip/twist a wire and cram it in the end and then just be sure they do not fall out before turning the key.
 
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KCSAse98gt

KCSAse98gt

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lets start simple. In the last pic directly above there are a number of unused harnesses which is normal. If you look at them you will see two thick black wires that are the only two to only have one wire connection. Those are grounds, one was for the deck and I am pretty sure the other went to the amp. Try grounding both of those and see if you get sound from it. All you need to connect is a simple male spade connector but to do a quick test you can just strip/twist a wire and cram it in the end and then just be sure they do not fall out before turning the key.
No luck, but I do appreciate the help. At least I can enjoy the sound of the exhaust until I get this figured out. Got an xpipe and pypes pype bomb put on.
 

ttocs

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just noticed something else in that pic it looks like you have the tweeter harness from the amp disconnected. Look at that last pic and see the large red/black 8 pin harness that almost looks like the radio power harness(except that one is grey). Look inside the dash and you should find a female mate to that harness. Plug those two back in and I bet your tweets come back on.
 
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KCSAse98gt

KCSAse98gt

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Thank you so much! I'm at work right now but I'll go try that on my lunch break.
 
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KCSAse98gt

KCSAse98gt

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It worked, thank you so much! Can't believe it was something so simple. I just assumed that connector went somewhere in the head unit which she had taken out. Found the connector tucked down below everything. Anyway I can send you a gift card or something? You certainly saved me a headache, had a lot of plans for the car but replacing the whole stereo wasn't one of them.
 

ttocs

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I believe in karma, you can "owe" me one and sooner or later its all good. That harness is the harness that goes from the front amp/cross over(below the radio) and then goes to the tweeters and the front subs. IF/when you decide to get rid of the mach system that harness is your ticket to make it easy. You can wire you speaker out from the deck into that harness and then just replace the door speakers and use the wire that went to the stock tweeters as the signal wire for the new speakers and the amps are bypassed, no need to run wire. If you start to have issues with the battery going dead look at the mach amps first as they are known to cause this.
 

Connie

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I believe in karma, you can "owe" me one and sooner or later its all good. That harness is the harness that goes from the front amp/cross over(below the radio) and then goes to the tweeters and the front subs. IF/when you decide to get rid of the mach system that harness is your ticket to make it easy. You can wire you speaker out from the deck into that harness and then just replace the door speakers and use the wire that went to the stock tweeters as the signal wire for the new speakers and the amps are bypassed, no need to run wire. If you start to have issues with the battery going dead look at the mach amps first as they are known to cause this.
I wish my brain worked as well as yours! I'm TERRIBLE when Electronics and Wiring become an issue. You helped me with a simple 5 year old Battery problem, that I thought was complicated. All because electronics frighten me. Bob.
 

ttocs

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its funny that wires have almost always seemed to fascinate me more than scare me. I think its because I remember the first time I was shocked and in a really weird way I think I kinda liked it but after that I just have not been all that afraid of electronics till we are in the 200v range. Now the Mechanics behind the engine and the understanding how it all works together is something a little more elusive for me...
 

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