Lights Dim after Big "2" Upgrade

[loopkiller 10+ year member]

OP I have a 97 Civic LX myself with about 950W RMS between 2 amps. I have an HC1400 under the hood, stock alt, and "Big 2" as well. I don't see any reason to upgrade the ALT+ to BATT+ since I still have the stock alt that can only push 70a. If I ever upgrade my alt, I will for sure upgrade that last wire with it.

When I first did my install years ago, I did not have a dedicated ground running from rear to front. I also had some dimming and alt noise then. After running a dedicated ground (2 AWG same as POS+) all the way to the front battery, the dimming and some ground noise disappeared. The Civic is notorious for terrible grounds at the trunk. There are too many wleds in between the trunk and the engine bay. You are just going to have to bite the bullet and buy another piece of wire to match your power wire and run a dedicated ground.

 

[KawabungaZX6R 10+ year member]

ok, I just got my DMM and set the amp's gain accordingly (31.6v) and started to check my voltage for alternator and battery....

Car Running & Lights On - 14.2-14.3v at Idle

When the bass hits hard it drops to 13 - 13.3v

Would a 1v drop cause lights to dim while driving or at idle on 500wRMS and 70amp alternator??? Is this normal??

 

[dcole18 5,000+ posts]

Hi, as the title says, I still have dimming occur after doing the Big "2" Upgrade with 1/0 AWG wire (Battery - to Ground and Engine to Ground) in my 98 Honda Civic. My system is only 500 RMS @ 2ohms but the headlights and interior lights dim when bass hits. I have installed a new battery and my alternator(70 amps) is fine. What else can I do?!?!?

you gotta upgrade the wire from your alt... just grab some jack stands and get under that bish

 

[gnatnoop 10+ year member]

the part of the big 3 you didnt do is the most important one (to stop voltage drops)