Trailblazer Radio Harness

EME · May 7, 2004

Would anyone here happen to have a wiring diagram of the 24pin radio wire harness for the '02 Trailblazer LS? There is also the second harness I'd like to know about.

Thanks!

blue2kzr2 · May 7, 2004

I can probably find it, gotta see if I can can save the image. I know i can print it out. What radio, it apparently DOES make a difference, at least as far as the GM eSI is concerned...

EME · May 7, 2004

It's a standard GM radio with Class II RDS and a CD player.

You should be able to print to a file or take a screen shot.

blue2kzr2 · May 7, 2004

Tried printing to file and got a 0 KB file. You'll need a TIFF viewer if you want me to send the HTF files. Irfanview is a good one, and free. It's at www.irfanview.com

EME · May 7, 2004

I've got a TIFF viewer.

EME · May 7, 2004

I've got a TIFF viewer.

EME · May 10, 2004

Ok, I got my new headunit all wired up but ran into a problem. It was all working fine and then all of a sudden it stopped working. I pulled the radio back out and found one of my wires to be dead. I played with it for about a half hour and power came back. All was fine and then later on it died again and eventually came back on. It's like the computer keeps turing off one of my wires or I'm tripping a breaker. I still had my factory stereo wired up so I could get the ding ding and it continued to work. This problem happens with or without the factory stereo plugged in.

The problem wire is the one that appears to supply ignition power. According to my meter, it is hot once the key is turned and turns off after the 10 or so minute delay after the engine is shut off. There is only one other wire that supplies power but it is continuous so would be for the memory. I don't understand how the factory unit continues to function when running off of the same wires and only a single hot wire active. I've tested above my splice to make sure it wasn't my splice that was causing the problem. Anyone have an idea why the circuit would be shutting off and if there is some mystery wire available?

I did find out that leaving the factory unit still attached for the ding ding isn't the best idea. The sound actually comes from the speaker in the driver's door. Having the speaker still connected to the factory unit causes the sound from the new stereo to be distored. A dedicated speaker would have to be used, or the expensive adapter or just not bother with it.

EME · May 11, 2004

I may have an idea of what is going on. Maybe the stock unit actually only uses a single power lead and the other one is used to run a relay. So inside the radio it could split into the two inputs but the second is set up with the relay controlled by the ignition. Does this sound like something that would be done?