No sound after adding aftermarket amplifier (Concert III)

[turtlebreath]

After installing a power pack amp (Pioneer gm-d1004), I get no sound from the front set (the rear set is still amped by stock boot amp).
Does the Concert III require resistors between the amp to work? I wish I tested it before dismantling my entire center console
Any input is appreciated.

 

[turtlebreath]

After a quick drive, it came to life! It turns out the battery must have been low due to corona mode. What a difference in the sound stage with that teeny amp. Going to write up a complete moron's guide to amping your front set and making a harness at some point.