Post Aux2Car Install Help

[MNBug]

Hello everyone, I know that this is an old topic but I need some help. Using posts from this forum I installed an AUX2CAR in my 2004 Vibe (single CD player) myself. Yellow constant wire to the blue/white stripe wire, and the ground wire to the brown ground wire.I'm not overly familiar with stereo installation but this didn't sound that hard. Got everything hooked up, tested it, everything seems to be working fine, however, after driving around for a little while and over some bumps I notice that my speakers kind of fade out and in. More specifically, I can hear sounds from the speakers but it is muffled and about half as loud. When I switch back to the CD or radio the sound is normal.I assume that I have a loose connection somewhere but where? In the harness? All the wires are there and connected. How do I test this, and more important, how do I fix this.Thanks much, Nick

[GMJAP]

Make sure1) The 12-pin harness is fully plugged into the back of the HU2) The circular connector is all the way into the AUX2CAR3) Your other other audio connections, like RCAs, are tight.