I have a 2002 dodge caravan sport, the radio was not tuning, so I purchased a Jensen HD radio with mounting kit, antenna adapter and wiring harness. The radio switches on, but there is no output on the speaker. On further checks I found that the white wire with black line on it enables the car amp as the car has a 6 speaker infinity system. The wire measures 1.2V when connected to the factory stereo. But there is no wire from the HD receiver connecting to this wire. What is the signal that is given by the factory stereo that enables the car amp to output to the speaker. Is there an adapter or any other part that simulates the signal so it activates the internal amp in the car.

Best Regards
Carasp