ARicci6792

Alright folks, any help on this would be awesome and very much appreciated because Ive been scratching my head on this for the past week now and cant figure it out.

Lets start of my saying I have a 1999 Mustang Gt with the Mach 460 system, I bought the car with an aftermarket headunit already installed. Pioneer DEH-4900IB to be exact. Nice decent headunit that sounded amazing with the Mach system.

Well I wanted a little more look to go with the great sound so I grabbed a used Jensen Vm9312 Flip Out. I go and wire everything up exactly how my Pioneer was, pop her in and what do ya know, Im having sound issues. I only seem to be getting sound out of the tweeters, and NO bass whatsoever. Almost like the amps arent being turned on. So I do some research and go buy a Metra 70-5510, the one that comes with the black plug with the RCA plugs instead of the wires. Hook it up, get a little bit of bass, but now NO volume. I can turn the headunit up to max (40) and itll sound like my Pioneer was on 10.

I cannot figure this out. I know the Jensen is only 17w RMS while the Pioneer was 22w, but I should still be getting full sound and bass shouldnt I? My next step is to order a new harness for the Jensen itself being that the one it came with was a little hacked up. Can someone link me to a full tutorial explaining this install with the exact parts needed?

I DO have one extra plug laying around in the back that looks exactly like the black 8pin for the speakers, except this one is a 6pin. Nothing was ever hooked up to it, even with the Pioneer and I got full sound...



Im losing my mind trying to figure this out so any help would be greatly appreciated!

xkape

Page 7 of this pdf is the wiring diagram for your exact headunit.

http://audiovox2.info/docs/common/VM9312/VM9312_OM.pdf

ttocs

well that would be accurate if he was not having issues with the mach system.
What you are running into is a problem their engineers put there on purpose, for this reason. The stock amps use a higher voltage input 6-8 volts. Your pioneer probably had a higher voltage output then the jensen did, or you were just feeding the speaker level output from the deck into the amps which is about what ford did.

Your original problem of NO bass would leave me to believe you didn't have the decks blue remote turn on wire to the cars amp turn on wire(could be blue/white double check). Your stock amps didn't know to turn on with out that wire connected. I suspect you connected that wire on the new hrns since you got the bass to work after installing it or you would have the exact same problem.

2 options here:

- Wire the original hrns up that I suspect used the speaker level inputs to feed the deck but be sure to connect your blue wires correctly this time.

- If you want to keep using the rca's for your signal you will need to invest in a small box called a line driver. It is basically a low-level amp that will just boost the signals voltage to a level the amps will be happy. The best one I know made is by phoenix gold. They have been makin them for years and I have used them both on my own vehicles and others.

ARicci6792

Thanks for the info guys. That was the wiring diagram I was originally going off of which is why I thought it was weird it wasn't working right. I just wired my Pioneer back up for the time being I got too frustrated lol.

The Amp turn-on wire was definitely hooked up that was one of the first wires I checked to make sure the connections were tight. I'm usually good with wiring radios/speakers etc I'm 110% it was all hooked up right. Anyone think it might be the headunit itself? Since no speakers or anything is blown due to them all working with the Pioneer.

ttocs

its easy enough to test the deck by connecting the power wires(red/yellow/black) to the batt and a small/cheap speaker.

Martin6107

The 99+ wiring is a bit tricky. Check this thread for a great description of the trickery.

http://mustangboards.com/show-shine-...-mustangs.html

You may need to hunt through your Head Unit manual to set the internal controls such as frequency bypass, inteernal amp, etc...