I am planning on buying an aftermarket GPS headunit... I was looking at crutchfield, and their install instructions state that if i install the unit, the factory sub will no longer work. how could this be since my sub is wired via daisy chain to the factory harness???

Is there a way around it to make the sub work with the AF HU??

 

I would think that if the HU you install has a feature to control a sub.

as for the OEM power and the HU.... you'd probably have to disconnect the one in the sub. Most after market HU's have amps built into to the HU. So I'd say go with that option, because you dont want to have 2 amps on the same physical line.

 

but why would it work with my factory HU since that doesnt have a "sub control"?