On the Alpine's instructions its stating that I need to plug the power wire directly into the battery. So does this mean I cannot splice the power wire from the alpine harness to the aftermarket honda harness? I included some pics to clarify.

Do I splice these two together (yellow wires) like I would with other installs or is Alpine telling me not to do this?



Aftermarket Honda harness (for my Accord not S2k)


Alpine harness

 

your alpine is more powerful than most OEM headunits, so alpine is
concerned that you can't safely draw sufficient current through
the factory wire, which is why they have you hook it directly to
the battery.
if you're using an external amp and can turn off the internal amp,
I think you'd be fine with the factory wire, but otherwise I'd probably
follow their advice and connect it directly to the battery.

 

run a line from battery, to the back of the HU, splice it into the thick yellow wire that goes into the alpine

 

ok I just spliced the wires since I really don't listen that loud. Unfortunately, I do not have a ext amp and the HU is powering the 4 OEM speakers. I am just going to wire everything through the honda harness. Thanks for your help guys.

 

if you have a multimeter you can measure resistance of the speaker, derive appropriate output voltage (to speaker) where power falls below 20w... note volume level... and if u generally play below that volume it should be okay