Hi, I just bought a 96 mustang 3.8L v6 ( don't laugh ) from a friend and I'm having trouble with it. It had the ford radio/cassette player ( no cd ) with the external factory amp but my friend ripped the radio and amp out and no longer has them or the harnesses so the space where the radio went is just wide open with a bunch of wires taped together. I found the eight speaker wires and marked them and then used a voltmeter to find the constant, acc., and illumination wires. The car has 3 ground wires coming from the bundle, two went to the radio and one to the amp. Also, the amp had a seperate 12v constant coming from under the driver side dash and of course the remote going to the radio and one of the ground wires. I tried to hook up a cheap sony head unit I had in my garage just to fill in the gaping hole in my panel and it worked, but my airbag light started flashing. I think maybe the 12v wire that went to the amp somehow completed the airbag circuit through the radio (?). Any way, I hooked the speakers up right, hooked up the constant,acc, and ground wires, and capped off the extra constant wire that went to the amp. I used a voltmeter to check the 3 ground wires and they're all good. Now, everytime I hook the battery back up, the alarm goes off real low and I can't turn it off ( like it does when the battery is dying ) but when I check the battery, It's still charged. I changed all the fuses that looked bad and I'm still having the same problem. Any suggestions? I understand that with the factory system you needed a bypass harness to use a new head unit because the wiring is a headache waiting to happen, but all I have is the wiring to work with and a sony headunit because the amp and radio are long gone. Please help!
Replies (15)
ttocs on 03/20/2008 01:21:05
oh dear god, do not let your friend touch your car again. you came to the right place as I own a 94 gt and I am more familiar with the mach system then anyone and this scares the hell outta me man...
First the airbag. There is nothing in the factory stereo that has ANYTHING to do with the airbags. The aribag wires are normally easily diagnosed by the bright yellow cover of the wires that is normally marked every 12" saying that it is an airbag wire and not to cut it. Open your glove box and look at the bottom of the bag and make sure that it is still plugged in but I am willing to bet that when you and yer buddy started cutting things that you cut the pass side wires. If this is the case you are really up the creek with out a paddle since most shops will not even try to help clean up an abortion(that is the industry technical term) like this.
Go to my cardomain page, ride #2395420 and page 2 shows what you should have done. Can you get pics of what is left in the dash wiring?
The three dimmer wires are actually probably one ground, one dimmer ground and one amp ground. Use a clean part of the chassis for your ground and just insulate these wires.
As for the alarm sound, it sounds as though your alarm ground was probably cut as well and it is now SEEKING its ground through the siren ground. It is common for the siren to make this noise if I have the siren hooked up, as well as the constant but not the ground on the alarm.
I need you to be completely honest with what you guys did here if we have any chance of keeping this car drivable. As it is right now with the airbag lights on it will not pass a state inspection if one is needed. I also need you and your buddy to realize that you have probably already done a fair amount of damage "just installing a stereo" and that you can do a whole lot more if you are not carefull.
djp1226 on 03/20/2008 14:42:24
An abortion?! Jeez, that does'nt sound gound. Well, I took the old sony back out, taped the exposed ends of the wires and changed some blown fuses I found. Now when I hook the battery back up the alarm goes off like normal, but now I can turn it off with the remote so it's working like normal.
As for the car, when I bought it from him it had a big ugly gaping hole where the radio was. He had tried to install an Alpine or something but couldn't get it to work so he gave up. I had a cheap sony headunit laying around and just wanted to "throw it in", thinking it'd be like any other car I had but I didn't know about the factory amp that was SUPPOSED to be there. It turns out he broke the face of the radio into little pieces trying to get it out with a "special tool" ( which turned out to be two bent pieces of coat hanger ) but one of the clips was broke or something. I'm not sure what he's talking about because I'm not familiar at all with the mustangs' radios. Then, finding out his speakers wouldn't work, he took the amp out and spliced directly into the speaker and power wires but couldn't get his head unit to work anyway. This was about 6 months ago. I just bought the car from him a week ago and tried to do the same thing with the sony, and it worked, but like I said, funny things happened.
I can take pictures for you, should I just email them? And as for the grounds, you said I should just make a new one so do you think it would hurt to just tape off the others?
bluecat1 on 03/20/2008 15:27:08
How is this for an idea. Try to get a hold of a schematic of your cars wiring. I found that they sell these books in autozones and strauss auto. If you yourself can not read the schematic, then I'm sure someone here can help you. Once you have located the wiring for the car audio/amp/speakers etc., you can get one of those harnesses from Cruthfields for the aftermarket HU you intend to install. You still may be able to salvage any mistakes you made with little patients and common sense. I found that going into projects with blinders on usually ends up in disaster. To know your vehicle is to love it. That $15 or $20 you invest in a Vehicle Tech book will save you hundreds in the long run.
Just another note: I commend you for trying to clean up someone else's mess. You gave it your best effort and I'm sure with the right tools you can succeed in completing your venture. The guys on this site have great knowledge and past experience.
Good luck!
djp1226 on 03/20/2008 15:57:44
Thanks for replying guys. I actually have some schematics bluecat, but they're in a Haynes manual and not very detailed when it comes to the audio system ( or any other system!). For instance, the schematics don't show the amp or where the power wire for it leads. This wire has me worried. I don't know what to do with it since I don't have an amp and I'm not sure if just taping it off and out of the way would hurt anything. I was never into car audio but it actually is fun trying to clean up this mess. I don't need to drive the car right now because I do have another so this isn't urgent but it is challenging for a non-tekkie like me. I hope you guys can help me get it together. As for pictures, I don't have a host but I can email them if you want to see what I'm dealing with. Thanks alot.
bluecat1 on 03/20/2008 16:51:01
I just googled your make and model car. I got 2 results that may help you.
www.ALLDATAdiy.com
www.Mobileinformationlabs.com
Here is a start where to get a schematic. I didn't get to much into the sites as I wanted to help you before I left work. If nothing pops up for you today, I will go to a friend of mine who has ALLDATA in the shop tomorrow.
djp1226 on 03/20/2008 18:50:12
Thanks alot, I'll check them out.
ttocs on 03/20/2008 21:10:21
dude those sites will be useless.... The wire colors are for basic and general colors they do not get into anything mach related.
Did you look at my cardomain page to see if you have anything that resembles what I show on page 2? You can post pics here now.
djp1226 on 03/21/2008 17:57:25
I sure did baldinstaller ( beautiful car by the way ). On the second page, third picture down where you're pointing to the speaker harness, I recognized it immediately. That's what I'm working it. Here's an update though, someone at work told me that when you disconnect the battery on these cars sometimes the airbag light flashes a 52 code that it has stored in memory and you have to clear it at the plug hanging under the glovebox. I'm going to try to find out how to do this and let you know if it works. It likely had nothing to do with the radio and I should've investigated this before I posted, I apologize.
The harness on the right in that picture is the one I've been fooling with because I already marked all of the speaker wires and tested them. In the top part of the plug on that harness ( that goes into the car, not the radio ) I have these colors:
Green---Constant 12v
Yellow/black----12v switched
black-------ground
green/black-----another ground
blue/red----illumination I assume
In the bottom part of the plug, where it goes to the radio, the colors are all the same except the green/black now branches off into two green/black wires, which leaves me with three grounds coming from there. One green/black wire went to the amp, and one to the radio. The radio also had a black ground. Why would the radio have two grounds, is one for the the illumination? That's what it seems like from the schematic in my hayne's manual ( interior lighting schematic, not the radio schematic ).
And last but not least, the harness on the sony head unit:
Yellow-----12v constant
Red---------12v switched
Black------Ground
Dark Blue--------amp remote
Blue/white---ant remote
Light blue---telephone mute
No illumination wire.
I'm going to take some pictures right now and I'll figure out how to post them. Thanks alot.
djp1226 on 03/22/2008 01:52:47
Well, here's where I am now. I went out today and got the radio working. I just hooked the radio up and capped off the two green/black grounds and used the plain black ground. The car is starting fine, the electrical components all seem to be working fine ( including the alarm ), but the airbag light is still flashing. I need to google it or something and find out how to reset the airbag diagnostic module codes ( if my coworker is right ). I think I pretty much have everything in order except that. I thank you guys for being patient with my ignorance and I hope to talk to you if I ever decide to upgrade ( I'll probably need ALOT of help ). Ya'll are awesome, take care.
ttocs on 03/23/2008 16:49:20
the airbag thing still scares me, never heard of problems after disconnecting the batt but....
Ok good, looks like you have the two hrns's that you need and have pretty much diagnosed all the wires you need. The extra ground is probably for the ill ground, just cap it off and insulate it, you will not need it. I would still run my own ground just to be safe. If you put a ring terminal on a wire, you can find a good ground location on either side of the consol behind the carpet, under the dash. Ford likes to use 3/8" screws that are colored green on top to notate their factory ground points. Just use that as your ground.
djp1226 on 03/24/2008 22:25:58
Yeah, the radio's working fine but I'll run my own ground just in case. I found continuity between a bunch of grounds in my car ( a/c, lighter, etc. ) and the metal bracket that the amp sat on. Does that mean it would be a good ground? And about the airbag, I read that if I took a small piece of wire and "shorted" the plug under the dash it would reset the airbag diagnostic module. I turned the key on ( didn't start it ) and put one end of the wire in the plug where I found voltage and put the other end on a ground. After a few seconds the module beeped and the code cleared. It hasn't come back on yet. I was scared the whole time that the airbag would explode in my face (!) but it didn't and I haven't had the problem again. I've been (finally) driving the car and after the rough ride ( computer "relearning" everything ) it started running perfectly. Now I just need to find a 5.0 and a standard transmission to throw in it...
Anyway, thanks again.
ttocs on 03/24/2008 23:34:16
Where are you getting this airbag info from? your playin with fire with the airbags mang.... Unless you are reading an email from a ford tech, I would not be grounding anything. That airbag is an explosive....
I am not sure why your computer would have to re-learn anything, I have had the battery out of my car and it still runs perfect. Mom took good care of the motor for the first 12 yrs before I got it, most mustangs are not....
Stick your head down by your pedals and look towads the back of the radio, and you will see a large green bolt that might even have another wire gounded to it. That is a great ground and it is inches from the radio. Leave yourself a good foot on the end of the ring terminal and you can cut the excess....
swez on 03/25/2008 06:43:06
When most car cumputers throw a code, (or several codes) it's because the computer has detected a fault that is actively out of sync with factory presets. In many cases, the computer codes can be reset by diconnecting the Neg battery terminal for a minute or so and then reconnect.
This often clears most minor codes and resets the computer to factory default settings. If the fault should reappear later, the system throwing codes needs to de checked out carefully by a qualified tech.
The best resource for the serious DIY'er is to buy the shop manuals for this vehicle and read up on the diagnostics trees that relate to the codes being triggered. These manuals will give the correct test procedures and exhaustive diagnosis steps to perform to find the root cause of the codes being triggered.
This can be a real time consuming process, but when you have such a book on hand, it's a real money saver if we have the patience, the proper tools and follow directions to the letter. Chilton's and Hayes books only cover the basics and generalities of most common car repairs. They often lack key details on specific models and cars with lots of electrical goodies in them.
Swez
PS Also look for any recent Tech Service Bulletins that are related to this vehicle. These come from Ford Engineering and explain the problem in detail and the corrective action steps needed to fix them properly. Most dealerships have them on hand or you can get them from Ford's website in most cases.
djp1226 on 03/28/2008 11:01:00
Sorry, I haven't been able to log in recently......
http://www.veryuseful.com/mustang/tech/airBag/airBag95.html#DiagCodeClearing
this is where I found the airbag information.I had a code 52. As for the computer , my car runs rough for the first five or ten minutes after I've had the battery disconnected. The ford manual ( Haynes ) said that it's because it has to relearn certain operating specs, etc. I don't know, it sounds weird to me too but it definitely runs better after the first drive so I guess they're right.
ttocs on 03/28/2008 15:57:02
I will call you brave because it seems to have worked but if it didn't that could be easily switched. That seems to have stuff written by anyone that wants to submit an article and they have a clear warnging on the front of their site that they have not tried this stuff and are not responsable....
Replies (15)
ttocs on 03/20/2008 01:21:05
oh dear god, do not let your friend touch your car again. you came to the right place as I own a 94 gt and I am more familiar with the mach system then anyone and this scares the hell outta me man...
First the airbag. There is nothing in the factory stereo that has ANYTHING to do with the airbags. The aribag wires are normally easily diagnosed by the bright yellow cover of the wires that is normally marked every 12" saying that it is an airbag wire and not to cut it. Open your glove box and look at the bottom of the bag and make sure that it is still plugged in but I am willing to bet that when you and yer buddy started cutting things that you cut the pass side wires. If this is the case you are really up the creek with out a paddle since most shops will not even try to help clean up an abortion(that is the industry technical term) like this.
Go to my cardomain page, ride #2395420 and page 2 shows what you should have done. Can you get pics of what is left in the dash wiring?
The three dimmer wires are actually probably one ground, one dimmer ground and one amp ground. Use a clean part of the chassis for your ground and just insulate these wires.
As for the alarm sound, it sounds as though your alarm ground was probably cut as well and it is now SEEKING its ground through the siren ground. It is common for the siren to make this noise if I have the siren hooked up, as well as the constant but not the ground on the alarm.
I need you to be completely honest with what you guys did here if we have any chance of keeping this car drivable. As it is right now with the airbag lights on it will not pass a state inspection if one is needed. I also need you and your buddy to realize that you have probably already done a fair amount of damage "just installing a stereo" and that you can do a whole lot more if you are not carefull.
djp1226 on 03/20/2008 14:42:24
An abortion?! Jeez, that does'nt sound gound. Well, I took the old sony back out, taped the exposed ends of the wires and changed some blown fuses I found. Now when I hook the battery back up the alarm goes off like normal, but now I can turn it off with the remote so it's working like normal.
As for the car, when I bought it from him it had a big ugly gaping hole where the radio was. He had tried to install an Alpine or something but couldn't get it to work so he gave up. I had a cheap sony headunit laying around and just wanted to "throw it in", thinking it'd be like any other car I had but I didn't know about the factory amp that was SUPPOSED to be there. It turns out he broke the face of the radio into little pieces trying to get it out with a "special tool" ( which turned out to be two bent pieces of coat hanger ) but one of the clips was broke or something. I'm not sure what he's talking about because I'm not familiar at all with the mustangs' radios. Then, finding out his speakers wouldn't work, he took the amp out and spliced directly into the speaker and power wires but couldn't get his head unit to work anyway. This was about 6 months ago. I just bought the car from him a week ago and tried to do the same thing with the sony, and it worked, but like I said, funny things happened.
I can take pictures for you, should I just email them? And as for the grounds, you said I should just make a new one so do you think it would hurt to just tape off the others?
bluecat1 on 03/20/2008 15:27:08
How is this for an idea. Try to get a hold of a schematic of your cars wiring. I found that they sell these books in autozones and strauss auto. If you yourself can not read the schematic, then I'm sure someone here can help you. Once you have located the wiring for the car audio/amp/speakers etc., you can get one of those harnesses from Cruthfields for the aftermarket HU you intend to install. You still may be able to salvage any mistakes you made with little patients and common sense. I found that going into projects with blinders on usually ends up in disaster. To know your vehicle is to love it. That $15 or $20 you invest in a Vehicle Tech book will save you hundreds in the long run.
Just another note: I commend you for trying to clean up someone else's mess. You gave it your best effort and I'm sure with the right tools you can succeed in completing your venture. The guys on this site have great knowledge and past experience.
Good luck!
djp1226 on 03/20/2008 15:57:44
Thanks for replying guys. I actually have some schematics bluecat, but they're in a Haynes manual and not very detailed when it comes to the audio system ( or any other system!). For instance, the schematics don't show the amp or where the power wire for it leads. This wire has me worried. I don't know what to do with it since I don't have an amp and I'm not sure if just taping it off and out of the way would hurt anything. I was never into car audio but it actually is fun trying to clean up this mess. I don't need to drive the car right now because I do have another so this isn't urgent but it is challenging for a non-tekkie like me. I hope you guys can help me get it together. As for pictures, I don't have a host but I can email them if you want to see what I'm dealing with. Thanks alot.
bluecat1 on 03/20/2008 16:51:01
I just googled your make and model car. I got 2 results that may help you.
www.ALLDATAdiy.com
www.Mobileinformationlabs.com
Here is a start where to get a schematic. I didn't get to much into the sites as I wanted to help you before I left work. If nothing pops up for you today, I will go to a friend of mine who has ALLDATA in the shop tomorrow.
djp1226 on 03/20/2008 18:50:12
Thanks alot, I'll check them out.
ttocs on 03/20/2008 21:10:21
dude those sites will be useless.... The wire colors are for basic and general colors they do not get into anything mach related.
Did you look at my cardomain page to see if you have anything that resembles what I show on page 2? You can post pics here now.
djp1226 on 03/21/2008 17:57:25
I sure did baldinstaller ( beautiful car by the way ). On the second page, third picture down where you're pointing to the speaker harness, I recognized it immediately. That's what I'm working it. Here's an update though, someone at work told me that when you disconnect the battery on these cars sometimes the airbag light flashes a 52 code that it has stored in memory and you have to clear it at the plug hanging under the glovebox. I'm going to try to find out how to do this and let you know if it works. It likely had nothing to do with the radio and I should've investigated this before I posted, I apologize.
The harness on the right in that picture is the one I've been fooling with because I already marked all of the speaker wires and tested them. In the top part of the plug on that harness ( that goes into the car, not the radio ) I have these colors:
Green---Constant 12v
Yellow/black----12v switched
black-------ground
green/black-----another ground
blue/red----illumination I assume
In the bottom part of the plug, where it goes to the radio, the colors are all the same except the green/black now branches off into two green/black wires, which leaves me with three grounds coming from there. One green/black wire went to the amp, and one to the radio. The radio also had a black ground. Why would the radio have two grounds, is one for the the illumination? That's what it seems like from the schematic in my hayne's manual ( interior lighting schematic, not the radio schematic ).
And last but not least, the harness on the sony head unit:
Yellow-----12v constant
Red---------12v switched
Black------Ground
Dark Blue--------amp remote
Blue/white---ant remote
Light blue---telephone mute
No illumination wire.
I'm going to take some pictures right now and I'll figure out how to post them. Thanks alot.
djp1226 on 03/22/2008 01:52:47
Well, here's where I am now. I went out today and got the radio working. I just hooked the radio up and capped off the two green/black grounds and used the plain black ground. The car is starting fine, the electrical components all seem to be working fine ( including the alarm ), but the airbag light is still flashing. I need to google it or something and find out how to reset the airbag diagnostic module codes ( if my coworker is right ). I think I pretty much have everything in order except that. I thank you guys for being patient with my ignorance and I hope to talk to you if I ever decide to upgrade ( I'll probably need ALOT of help ). Ya'll are awesome, take care.
ttocs on 03/23/2008 16:49:20
the airbag thing still scares me, never heard of problems after disconnecting the batt but....
Ok good, looks like you have the two hrns's that you need and have pretty much diagnosed all the wires you need. The extra ground is probably for the ill ground, just cap it off and insulate it, you will not need it. I would still run my own ground just to be safe. If you put a ring terminal on a wire, you can find a good ground location on either side of the consol behind the carpet, under the dash. Ford likes to use 3/8" screws that are colored green on top to notate their factory ground points. Just use that as your ground.
djp1226 on 03/24/2008 22:25:58
Yeah, the radio's working fine but I'll run my own ground just in case. I found continuity between a bunch of grounds in my car ( a/c, lighter, etc. ) and the metal bracket that the amp sat on. Does that mean it would be a good ground? And about the airbag, I read that if I took a small piece of wire and "shorted" the plug under the dash it would reset the airbag diagnostic module. I turned the key on ( didn't start it ) and put one end of the wire in the plug where I found voltage and put the other end on a ground. After a few seconds the module beeped and the code cleared. It hasn't come back on yet. I was scared the whole time that the airbag would explode in my face (!) but it didn't and I haven't had the problem again. I've been (finally) driving the car and after the rough ride ( computer "relearning" everything ) it started running perfectly. Now I just need to find a 5.0 and a standard transmission to throw in it...
Anyway, thanks again.
ttocs on 03/24/2008 23:34:16
Where are you getting this airbag info from? your playin with fire with the airbags mang.... Unless you are reading an email from a ford tech, I would not be grounding anything. That airbag is an explosive....
I am not sure why your computer would have to re-learn anything, I have had the battery out of my car and it still runs perfect. Mom took good care of the motor for the first 12 yrs before I got it, most mustangs are not....
Stick your head down by your pedals and look towads the back of the radio, and you will see a large green bolt that might even have another wire gounded to it. That is a great ground and it is inches from the radio. Leave yourself a good foot on the end of the ring terminal and you can cut the excess....
swez on 03/25/2008 06:43:06
When most car cumputers throw a code, (or several codes) it's because the computer has detected a fault that is actively out of sync with factory presets. In many cases, the computer codes can be reset by diconnecting the Neg battery terminal for a minute or so and then reconnect.
This often clears most minor codes and resets the computer to factory default settings. If the fault should reappear later, the system throwing codes needs to de checked out carefully by a qualified tech.
The best resource for the serious DIY'er is to buy the shop manuals for this vehicle and read up on the diagnostics trees that relate to the codes being triggered. These manuals will give the correct test procedures and exhaustive diagnosis steps to perform to find the root cause of the codes being triggered.
This can be a real time consuming process, but when you have such a book on hand, it's a real money saver if we have the patience, the proper tools and follow directions to the letter. Chilton's and Hayes books only cover the basics and generalities of most common car repairs. They often lack key details on specific models and cars with lots of electrical goodies in them.
Swez
PS Also look for any recent Tech Service Bulletins that are related to this vehicle. These come from Ford Engineering and explain the problem in detail and the corrective action steps needed to fix them properly. Most dealerships have them on hand or you can get them from Ford's website in most cases.
djp1226 on 03/28/2008 11:01:00
Sorry, I haven't been able to log in recently......
http://www.veryuseful.com/mustang/tech/airBag/airBag95.html#DiagCodeClearing
this is where I found the airbag information.I had a code 52. As for the computer , my car runs rough for the first five or ten minutes after I've had the battery disconnected. The ford manual ( Haynes ) said that it's because it has to relearn certain operating specs, etc. I don't know, it sounds weird to me too but it definitely runs better after the first drive so I guess they're right.
ttocs on 03/28/2008 15:57:02
I will call you brave because it seems to have worked but if it didn't that could be easily switched. That seems to have stuff written by anyone that wants to submit an article and they have a clear warnging on the front of their site that they have not tried this stuff and are not responsable....
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