should i connect straight to the battery or use the power line in the harness? i'm about to install the pioneer deh 780mp, and if i don't have to connect to the battery, it will be less work. thanks...

 

For a lower power HU, the factory power connection is fine. I believe some of the higher end Alpines require an extra line to the battery.

If you plan to Amp the HU, you can definatly use the factory power as the amp will take the bulk of the work away from the HU.

 

I also have an Alpine but connected to amps. then u can use the factory power connection.
without amps it shouldn't be a problem but Alpine say you have to so they don't get slaims when your car goes up in smoke

 

What does the Pioneer manual say?

 

That HU does not need to be feed from the battery. You can use the harness power.