98 Yukon radio problems need help

[Shooter970]

I just bought a 98 Yukon the radio in it would come on but no sound, I bought a new radio installed it and same problem. I took a 9v battery and the front door speakers sounded and the ones over the back doors sounded but not the rear doors? Current goes to speaker but it still does not play? I hooked up the blue wire from the factory harness and I could hear something under the dash turn on but still no sound, UGh!

 

[SunlitComet]

where did you apply the battery power to? harnesses at radio? and what blue wire. the only blue i see is light or dark blue to the rear right roof speaker. if you are taliking about the possibility you have the factory amp that wire is pink and runs its relay. the amp is fed from the cig lighter fuse #13 20a. i assume you mean front door and rear roof speakers work but not rea side doors. that would be the factory amp issues. the amp is located under the drivers seat.

 

[Shooter970]

The blue wire on the radio harness adapter. So I should power a pink wire from the factory harness correct? Where is the relay because the factory radio did the same thing no sound but everything else worked

 

[SunlitComet]

gotcha typically,using the standard coloring scheme in use today, the solid blue wire triggers a motorized antenna and is not activated unless tuning radio. there is a blue/white stripe wire that is used for amp activation. if that is what you got, or look at instruction for harness, attach that to the pink wire on the chassis side harness. the power relay is buried big time. check the fuse i mentioned, make sure you are using the right trigger wire on the harness. see what happens. make the amp is still there. if still not working correctly check for volts on orange wire on amp harness with system running. if you really do need to get to relay it is going to be fun. the pic below give a general idea. btw it may change after a few hours.

 

[Shooter970]

Ok thanks if that dosent work I think I'll run new wire to the door speakers and try to find the roof speaker wire and tie into the do you have any idea where they are located