Why are my lights dimming with my subs in my 2003 Chevrolet Trailblazer?

[DirtyBlazer09]

I have a 2003 Chevy Trailblazer and 2 Alpine type E 12 Subwoofers.
The amp is an Alpine MRP-M850. When I turn the music up loud at night, the headlights and dash lights flicker, sometimes badly. I had the same exact system in my old 1996 Chevy Blazer, whose alternator has an output of 100-105 amps. My new Trailblazer has an alternator output of 135-150 amps. We also just replaced the battery in the Trailblazer. Why do my lights dim in the new Trailblazer when they didn't in my old Blazer?

[tcbassist]

Upgrade the alternator. Your vehicle has a lot of OEM electronics that consume a lot of that 135-150 amps already. Your amplifier just adds to that. Also upgrade the wire from the battery (+) to the alternator and from the battery (-) to the chassis. The stock wire is usually only 8 ga and with the added current draw of addition equipment they need to be 4 ga.

[Cap]

Upgrade the altenator to a high output alt.

[repentant sinner]

why not just get a capacitor and cut out all the guesswork?

[James G]

check and make sure all your ground wires are properly grounded to a chassis ground that will make an excessive current draw from the vehicle from your system that would be the 1st thing i would check