Car Stereos: added sub to gti monsoon, rca cables, knee jerk reaction

Question
I thought I new exactly what i was doing, unfortunately my gti is different than my lancer. I ran all my wiring with no problems. I bought an LOC to get my RCA cables run. However, the dealer couldn't get my head unit out. So instead I decided I'd tie in at the stock amp in the rear. I connected to the rear subwoofers outputs on the output harness. Before hooking up the amp i plugged the connector back in to make sure I had good connections. Everything worked perfect. As soon as i hooked up my aftermarket amp i lost my front door woofers. This is why i am confused... I tied into the rear door woofers, but lost the signal to my front woofers. Any suggestions?

Answer
Hi Morgan,

The knee-jerk reaction I have is, 'check your wiring again'.  Sounds to me like you infact tied into your fronts.

The issue you may be dealing with is the LOC is causing an impedance drop in the circuit, and so the amplifier is freaking out and turning that channel off.

So the best I can really say is re-check your wiring -- maybe you've tapped the wrong wire?  VW is notorious for using the same colour twice in the same harness.