Me and my dad are at a lost... I have a 1998 Jeep Cherokee Classic 4.0 My factor radio works fine except the rear speakers. Recently I have been wanting subs in my Jeep. So I but the pionner 150mp and bought the Metra 70-1817 wiring harness. Far as we know we wired everything up correctly and according to some YouTube installs it is correct to what they have. We plug it on have a proper ground and everything. We had problems with same aftermarket radio before. But it was defective. So we took it back. And got the same one. We plugged it up in the morning. It worked then we go ahead install the subs with amp and all. We plug in the radio. It doesn't work. The subs played sound but no music from regular speakers. No static... Nothing. We unplug the subs still nothing no music. So we order a different brand radio. As the one was out for delivery we had my friends 98 grand cherokee. Plug in his radio and harness(same brand and model harness as mine) and doesn't work... Same issue. He then plugs in back into his Jeep and works again. So we get my harness and my pionner radio and it works in his Jeep. But we plug in my factor radio in mine again. And music is there. We are at a total lost. Please help.
THANK YOU

 

Did you ever figure out the cause? I installed a pioneer head unit in my XJ and everytime I press the brake pedal, the speakers turn off.

 

You probably shorted out one of the speaker wires to the brake pedal wire for some reason. I had an issue with my sons stereo and found that I had put a screw through the speaker wire that ran to the overhead speakers.