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Harness help

wt

New Member
Joined
Nov 4, 2013
Messages
6
Help me guys! Bought a new Sony stereo unit, install kit, and harness. I got the adapter harness connected to the sony harness fine, removed the factory Delco unit, and plugged the new harness plug to the truck harness.  But I got no sound. There was another small flat plug in the rear of the factory radio that has nowhere to plugged in now; retried the delco, and it wont give sound without it plugged in either. According to Crutchfield, Amazon , etc. I have the correct harness
(Metra 70-185:cool:. What is the small flat plug? And ideas?????  :help:
 
You have to do the "amp bypass" mod on a 2002.. Look here and/or do a search...


http://chevyavalanchefanclub.com/cafcna/index.php/board,161.0.html
 
Flat plug could be ONSTAR stuff...

 
Yes, I believe the other plug interfaces the COnStar and possibly the amp..

That's why you have to do the amp bypass on an 02 unless you are running new wire to the speakers or using external amps via patch cords.. Otherwise you will not have any sound..

The easyest way is to use the Metra 70-2021 plug and rework one side of the pins (relocate them in the plug see attached pics). The connector is under behind the glove box..

The lower pic says 70- 2002, you can modify that one also but the 70-2021 is already done for you, it just needs the pins moved..
 

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  • Metra 70-2021 (300x300).jpg
    Metra 70-2021 (300x300).jpg
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  • amp by pass.png
    amp by pass.png
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Thanks fellas!  Got the 70-2002 harness at Best buy, re-pinned it, and tried the install again. SUCCESS!!!!!!! Not the funnest thing Ive ever done ( big hands with corndog fingers), but not too bad. Thanks again!!!!!
 
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