Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 20 of 31 Posts

·
Registered
2005 chevy trailblazer_ls
Joined
·
274 Posts
Discussion Starter · #1 · (Edited)
Hello All. I Finally Figured Out How To Post A Question. I Need Some Help Installing my Dual XDMA7715 After Market Stereo. What kind of wiring harness can i use to make my new Dual stereo work? I have heard of the 70-2003 plug. Does that work with the 05 Trailblazer? and what is this OEM black connector for anyway?

Its the black connector one. It was connected to the factory stereo and dont know if i need to get a connector for this too. I hope someone has had experience installing a aftermarket stereo and can help me out. Thanks Much
 

·
Registered
2003 chevy trailblazer_lt
Joined
·
425 Posts
do you have onstar? Bose? stearing wheel controls? i think the black plug is the signals for the chimes(left key in , low gas, and so on)
 

·
Registered
2005 chevy trailblazer_ls
Joined
·
274 Posts
Discussion Starter · #3 · (Edited)
do you have onstar? Bose? i tink the black plug is the signals for the chimes(left key in , low gas, and so on)
No onstar or bose or steering wheel controls either. i have the black connector disconnected right now and am trying to figure out what it is for. The chimes still work. Weird because i thought thats what it was for also. :undecided Anyone else have an idea?
 

·
Registered
2003 chevy trailblazer_lt
Joined
·
425 Posts
i have no idea. i dont even have any of the wires on the black one connected to anything on my alpine headunit. i used the metra 70-2003 harness to connect my alpine HU. it works fine for me, the chimes dont work but i dont care and did not want to shell out $75 bucks to make them work. if you do use the 70-2003 the red wire(switched 12volt) needs to be spliced into the pink wire under the steering wheel
 

·
Registered
2005 chevy trailblazer_ls
Joined
·
274 Posts
Discussion Starter · #7 ·
i have no idea. i dont even have any of the wires on the black one connected to anything on my alpine headunit. i used the metra 70-2003 harness to connect my alpine HU. it works fine for me, the chimes dont work but i dont care and did not want to shell out $75 bucks to make them work. if you do use the 70-2003 the red wire(switched 12volt) needs to be spliced into the pink wire under the steering wheel
Thank you so much for the information. I wont worry about that black connector wires at all. I just have two more quick questions. Why do you think that the chime is taped into the radio for? that doesnt make any since to me. I prefer not to have the chime either. its very annoying at times plus the price to have it is outrageous like you said. Also. why would you have to splice the red wire into the pink wire under the steering wheel? just curious. So now that i know that someone has used the 70-2003 harness and it works is good enough for me to buy it and use it for my Dual unit. Thanks so much. you have been a big help. :thumbsup:
 

·
Registered
2003 chevy trailblazer_lt
Joined
·
425 Posts
Thank you so much for the information. I wont worry about that black connector wires at all. I just have two more quick questions. Why do you think that the chime is taped into the radio for? that doesnt make any since to me. I prefer not to have the chime either. its very annoying at times plus the price to have it is outrageous like you said. Also. why would you have to splice the red wire into the pink wire under the steering wheel? just curious. So now that i know that someone has used the 70-2003 harness and it works is good enough for me to buy it and use it for my Dual unit. Thanks so much. you have been a big help. :thumbsup:
glad to help:tiphat. i dont know why it is taped into the radio. you have to splice the red wire to the pink wire because there is not a switched 12 volt in the harness. there is a consonant 12volt(orange i think) that is always hot. and the switched wire is only like 4volts not enough to power the radio. so you have to coonect the red wire to the pink so it turns on and off with the car. if you connect to the orange the radio be on all the time.
 

·
Registered
2003 chevy trailblazer_ls
Joined
·
497 Posts
Thank you so much for the information. I wont worry about that black connector wires at all. I just have two more quick questions. Why do you think that the chime is taped into the radio for? that doesnt make any since to me. I prefer not to have the chime either. its very annoying at times plus the price to have it is outrageous like you said.
These vehicles use a serial data bus. Basically, different components "talk" to each other on a network. The radio uses this data bus for functions such as retained-accessory power. And from a cost-standpoint, it makes sense to use it for chimes, as well.

Also. why would you have to splice the red wire into the pink wire under the steering wheel? just curious. So now that i know that someone has used the 70-2003 harness and it works is good enough for me to buy it and use it for my Dual unit. Thanks so much. you have been a big help. :thumbsup:
The factory head unit uses the data bus to known when to turn on/off. The harnesses that we use to retain chime must interface with the data bus, and consequently are engineered to provide a switched 12V "acc" source to facilitate easy aftermarket head unit integration. If you don't use the adapter, you do would have to source an "acc" source elsewhere. The pink wire under the steering column is one choice, but some people do not recommend it due to the current draw and potential to cause the ignition switch to fail. Alternatively, you could source switched 12V power from the rear fuse panel... But I have heard that blowing that fuse will prevent you from turning the vehicle off!

A proper harness can be purchased for around $40. In my opinion, it is the proper way to go! With the harness, you don't risk damaging your ignition or losing the ability to turn your engine off!
 

·
Registered
2003 chevy trailblazer_lt
Joined
·
425 Posts
YOU WILL ALSO NEED AN ANTENNA ADAPTER. also all the wires on the metra 70-2003 have what they are for printed right on the wire. and the headunit wiring diagram tells what the wires coming out of the HU are for if not printed on the wires also. and the colors match up. it is really easy to understad and simply to wire up. i used butt connectors to connect the radio wires to the 70-2003 harness outside of the truck on a work bench so all i had to do was plug it in and connect the red wire
 

·
Registered
2003 chevy trailblazer_lt
Joined
·
425 Posts
These vehicles use a serial data bus. Basically, different components "talk" to each other on a network. The radio uses this data bus for functions such as retained-accessory power. And from a cost-standpoint, it makes sense to use it for chimes, as well.



The factory head unit uses the data bus to known when to turn on/off. The harnesses that we use to retain chime must interface with the data bus, and consequently are engineered to provide a switched 12V "acc" source to facilitate easy aftermarket head unit integration. If you don't use the adapter, you do would have to source an "acc" source elsewhere. The pink wire under the steering column is one choice, but some people do not recommend it due to the current draw and potential to cause the ignition switch to fail. Alternatively, you could source switched 12V power from the rear fuse panel... But I have heard that blowing that fuse will prevent you from turning the vehicle off!

A proper harness can be purchased for around $40. In my opinion, it is the proper way to go! With the harness, you don't risk damaging your ignition or losing the ability to turn your engine off!
the red wire is only used to tell the radio to turn on. the radio uses the constant 12 volt wire to actually power the radio.(kinda like a relay) i checked it with an amp meter and there is almost no current being added to that circut.
i have been running with this harness for a year and not had a single problem
 

·
Registered
2003 chevy trailblazer_ls
Joined
·
497 Posts
the red wire is only used to tell the radio to turn on. the radio uses the constant 12 volt wire to actually power the radio.(kinda like a relay) i checked it with an amp meter and there is almost no current being added to that circut.
i have been running with this harness for a year and not had a single problem
depends HEAVILY on the head unit. I've seen them draw <100mA, and over 3A!

Metra only provides about 2A on their switched acc lead, and they have a blurb in their manual about adding a relay for head units that demand more power.
 

·
Registered
2005 chevy trailblazer_ls
Joined
·
274 Posts
Discussion Starter · #14 ·
glad to help:tiphat. i dont know why it is taped into the radio. you have to splice the red wire to the pink wire because there is not a switched 12 volt in the harness. there is a consonant 12volt(orange i think) that is always hot. and the switched wire is only like 4volts not enough to power the radio. so you have to coonect the red wire to the pink so it turns on and off with the car. if you connect to the orange the radio be on all the time.
Just had a thought. What else does that pink wire under the steering actually operate? any ideas? :undecided Also The radio came with an antenna adapter. Thanks for your concern
 

·
Registered
2003 trailblazer_lt
Joined
·
9,856 Posts
What else does that pink wire under the steering actually operate? any ideas? :undecided
Ignition 1 supplies power to several powertrain components when the key is in the run position. This circuit is very important. If it is interrupted or is overloaded and blows its fuse (fuse 36) the truck will not run. This is why it is important that this circuit be tapped properly....the westinghouse split is the only method that should be used.
 

·
Registered
2005 chevy trailblazer_ls
Joined
·
274 Posts
Discussion Starter · #16 ·
Ignition 1 supplies power to several powertrain components when the key is in the run position. This circuit is very important. If it is interrupted or is overloaded and blows its fuse (fuse 36) the truck will not run. This is why it is important that this circuit be tapped properly....the westinghouse split is the only method that should be used.
What do you mean the westinghouse split?
 

·
Registered
2005 chevy trailblazer_ls
Joined
·
274 Posts
Discussion Starter · #20 ·
metra gmrc-01. you can get em on ebay for $40ish.
Is this what you use for your trailblazer? So if i get this then i wont have to find an alternate power source as far as taping into the pink wire under the steering wheel? i wont have to do that right? i could just plug and play and i could play the radio using the accessory power when my car is off also right? am i correct on everything? Thanks ;)
 
1 - 20 of 31 Posts
Top