I bought a plug adapter from circuit city for a new stereo to put in my 2003 chevy express van, and the guy told me I would have to run an asscessory wire from the ignition to turn on the new stereo. I have a total of eleven wires coming out of the dash. Eight of them are supposedly speaker wires (four that I'm sure of), one hot, one ground, and the last I can't get a reading on except to say that when I touch it to a neg or pos it makes my gauges and dash lights freak out. My question is how did the stock stereo turn on without some form of remote wire from the ignition?
I have the stereo hooked-up and it works. The only reason I'm inquiring is because now the buzzer when I leave the lights on doesn't work. I don't know if there is any connection between the two or if maybe I blew a relay or something. Any insight to the mysteries of my wires would be greatly appreciated.
Replies (5)
ttocs on 07/31/2003 09:58:46
you blew a fuse it sounds like. The last wire is probably the dimmer wire. By touching it to the other two, you are sending voltage into the circuit and turning the lights on and off. Are you making your voltage tests with the key on, or off?
dddrew on 07/31/2003 13:53:40
That was my original thought, but when I hooked it to the dimmer on my new stereo nothing happened. It's a thin wire compared to the rest, and if I'm reading the schematics I got from Chevrolet correctly, then it has something to do with the Data Link Communications. Regardless if it is a dimmer or not, I still don't understand how the stock stereo turned on. After the eight speaker wires, the constant positive and negative, this one wire is all that is left. If it is a dimmer then what turned the stock stereo on? If it isn't a dimmer, then why isn't it turning my new stereo on? Why did the installer at Curcuit City tell me I would have to run a wire from my ignition? And could this one wire be responsible for turning the stereo on and off with the key as well as when I open the door after the engine is off? I did pull all the fuses out one by one, and unless there's other fuses I don't know about, all the ones I checked were good.
_Robbob_ on 07/31/2003 15:32:18
like ttocs had stated earlier did you check the voltage with the key on or off...
I find it odd that a radio does not have a remote acc wire...did the original turn on without the keys turned on in the ignition...
Many of the newer factory radios stay on now untill the door is opened i'm not up-to-date on the system but hooking that last wire up might not have been a good idea esp if it said it was a data connection.
I'm going to try to look up the wire charts now that i'm curious
Swez on 07/31/2003 17:17:45
As you said, there are 8 wires for the speakers, then you will generally see the following:
1. Main power wire (Red) to IGN/ACC feed or fuse box for radio
2. Ground (Black)
3. Orange is constant power ON for station memory and clock time holding voltage
4. Yellow wire is ILL for dimming functions off the dash light panel
5. Blue wire is amp remote turn on
6. Blue w/ white stripe is for power antenna
"and the last I can't get a reading on except to say that when I touch it to a neg or pos it makes my gauges and dash lights freak out".
This is probably the dimmer function for the original HU. It may also be hooked up to dome lights as well.
The installer at CC may have been correct in terms of how they install power feed to new HU's. But in most cases, that wire is part of the original harness and is tapped most often to a wire off the fuse box. The newer cars/trucks do have a delayed shut off function whereby the stereo stays on with key off (or out) until the door is opened. Probably a delayed timmer function which is disabled one the door is opened or the timmer expires.
The serial data bus link is usually connected to ECM, BCM or Air bag computer functions. There might be a display link from the computers to read out data from the OEM radio display.
As mentioned before, check all fuses in fuse box and under the hood. Most fuses under the hood are engine control, headlights, cooling fan fuses/relays etc. Some low current fuses may look good at first, but if you take a continuity tester to them, then you'll know for sure if good or bad. Most Stock HU's use 7.5-10A fuse ratings. That's the one you want to find and test.
Finally, Alpine has a newer HU out that has very high output amps in the HU. It requires a 25A fuse and #10 gage wire for power. If you have one of these, that might be why the Tech at CC mentioned running a speprate wire for power here???
Swez
PS Keep digging an make sure you have a body/floor pan ground for the new HU. OEM units often ground to the wiring harness off display panel etc. Not always adequate for new HU's.
dddrew on 08/2/2003 14:44:07
FYI: I talked to several people and found out that the constant power wire has a higher voltage or amps or something when the key is on. The radio detects that and thats what turns it on. The small wire that made my dash lights freak out is actually quite important and can cause my airbags to go off or not work at all. And finally, the door buzzer worked through the speakers, and I'm told there isn't a harness yet that will make it all work with an aftermaket radio. So I'm stuck with the stock one until around January when a harness may or may not come out. Thanks for the help though.
I have the stereo hooked-up and it works. The only reason I'm inquiring is because now the buzzer when I leave the lights on doesn't work. I don't know if there is any connection between the two or if maybe I blew a relay or something. Any insight to the mysteries of my wires would be greatly appreciated.
Replies (5)
ttocs on 07/31/2003 09:58:46
you blew a fuse it sounds like. The last wire is probably the dimmer wire. By touching it to the other two, you are sending voltage into the circuit and turning the lights on and off. Are you making your voltage tests with the key on, or off?
dddrew on 07/31/2003 13:53:40
That was my original thought, but when I hooked it to the dimmer on my new stereo nothing happened. It's a thin wire compared to the rest, and if I'm reading the schematics I got from Chevrolet correctly, then it has something to do with the Data Link Communications. Regardless if it is a dimmer or not, I still don't understand how the stock stereo turned on. After the eight speaker wires, the constant positive and negative, this one wire is all that is left. If it is a dimmer then what turned the stock stereo on? If it isn't a dimmer, then why isn't it turning my new stereo on? Why did the installer at Curcuit City tell me I would have to run a wire from my ignition? And could this one wire be responsible for turning the stereo on and off with the key as well as when I open the door after the engine is off? I did pull all the fuses out one by one, and unless there's other fuses I don't know about, all the ones I checked were good.
_Robbob_ on 07/31/2003 15:32:18
like ttocs had stated earlier did you check the voltage with the key on or off...
I find it odd that a radio does not have a remote acc wire...did the original turn on without the keys turned on in the ignition...
Many of the newer factory radios stay on now untill the door is opened i'm not up-to-date on the system but hooking that last wire up might not have been a good idea esp if it said it was a data connection.
I'm going to try to look up the wire charts now that i'm curious
Swez on 07/31/2003 17:17:45
As you said, there are 8 wires for the speakers, then you will generally see the following:
1. Main power wire (Red) to IGN/ACC feed or fuse box for radio
2. Ground (Black)
3. Orange is constant power ON for station memory and clock time holding voltage
4. Yellow wire is ILL for dimming functions off the dash light panel
5. Blue wire is amp remote turn on
6. Blue w/ white stripe is for power antenna
"and the last I can't get a reading on except to say that when I touch it to a neg or pos it makes my gauges and dash lights freak out".
This is probably the dimmer function for the original HU. It may also be hooked up to dome lights as well.
The installer at CC may have been correct in terms of how they install power feed to new HU's. But in most cases, that wire is part of the original harness and is tapped most often to a wire off the fuse box. The newer cars/trucks do have a delayed shut off function whereby the stereo stays on with key off (or out) until the door is opened. Probably a delayed timmer function which is disabled one the door is opened or the timmer expires.
The serial data bus link is usually connected to ECM, BCM or Air bag computer functions. There might be a display link from the computers to read out data from the OEM radio display.
As mentioned before, check all fuses in fuse box and under the hood. Most fuses under the hood are engine control, headlights, cooling fan fuses/relays etc. Some low current fuses may look good at first, but if you take a continuity tester to them, then you'll know for sure if good or bad. Most Stock HU's use 7.5-10A fuse ratings. That's the one you want to find and test.
Finally, Alpine has a newer HU out that has very high output amps in the HU. It requires a 25A fuse and #10 gage wire for power. If you have one of these, that might be why the Tech at CC mentioned running a speprate wire for power here???
Swez
PS Keep digging an make sure you have a body/floor pan ground for the new HU. OEM units often ground to the wiring harness off display panel etc. Not always adequate for new HU's.
dddrew on 08/2/2003 14:44:07
FYI: I talked to several people and found out that the constant power wire has a higher voltage or amps or something when the key is on. The radio detects that and thats what turns it on. The small wire that made my dash lights freak out is actually quite important and can cause my airbags to go off or not work at all. And finally, the door buzzer worked through the speakers, and I'm told there isn't a harness yet that will make it all work with an aftermaket radio. So I'm stuck with the stock one until around January when a harness may or may not come out. Thanks for the help though.
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