Revs dip/lights dim every few seconds - only when sound system is on

[euromandeluxe]

Hey guys, problem with the electronics in my S2000,

When idling with the stereo on (but volume turned to zero) both the revs dip and cabin/cluster/dash lights dim every 2-3 seconds. I can hear the revs dip, but they only drop visibly on the tacho now and then.

When the stereo is off, the idle is absolutely fine (normally at around 900-1000rpm or so). Night and day difference.


http://www.youtube.com/watch?v=DwbwDe75UTs&feature=player_embedded

If you listen real carefully you can hear the revs dipping.


A bit of background: I'm running an upgraded stereo that I self-installed a few months ago (April?) - this idle problem only showed itself last week.

My system is:

- Infinity component speakers up front (90W RMS x2 @ 2ohms) powered by a 2 channel Kicker amplifier (capable of 100W RMS x2 @ 2ohms) - the Kicker is turned on by 'Signal Sense' (no remote turn on lead, as the sub's amp and antenna amp maxxed out the headunit's remote turn on output current).

- 12" Polk sub run by a Pioneer monoblock amp (~200W RMS I believe - I didn't purchase this kit myself, came with my previous car and simply installed in the S). Links for the sub and amp specs are:
sub: http://www.polkaudio.com/caraudio/specs/recent/db124dvc/
amp: http://www.audiocom.com.au/d534/pioneer-gm-d7400m-amplifier/

All through a Pioneer headunit.

No other electrical mods on the car.

Any idea what's wrong here? Battery, alternator, shitty grounds? I'm worried about damage to the rest of the car's electronics.

I'll go get the battery checked in the next few days when I have time.

Rep points up for grabs for good knowledge!
Thanks :thumbsup::thumbsup:

[2MPRS]

im having the same probably but its only when my bass turns on (i have 1600rms of just bass in my civic lol) from what ive been reading on the net the easiest and simpliest mod is to do the big 3 upgrade (google it lots of info and videos) try that out first easiest to do. if that fails try getting a bigger battery designed for systems. dont bother with farad caps they just kill ur alternator and do eff all.
ill be doing the big 3 upgrade in a week or 2 so if u dont do it before then ill tell u how it turns out

btw i just watched the video change the ground on the amps to a new location btw whats the wiring size on ur amps?

[euromandeluxe]

thanks for the tips man, too much bass! lol, i guess i'll do the grounds later this week if i can. i find it weird how this happens even when the system's on zero volume where the speakers aren't pulling any power at all.

i can't remember the gauge of the wires, but it's either 4 gauge or 8 gauge. i do remember that i made sure to follow the amp's specifications for gauges when wiring it up.

hmm, still pretty stumped on this.

[2MPRS]

if ur running 4-8gauge u should be fine. check ur earths if that fails double check the power wires cause it might be a loose connection somewhere and its not getting constant power.

[fromdeeeast]

With the system in the s2000, does it rattle much from the bass.

[arverson]

your systems definitely putting extra strain on the electrical system by the sounds of it

try upgrading the 'big 3'

hows the battery? stock battery right? ever run the system without engine running? it might be on its way out

how the alt? might need a recondition but i doubt this is the case

but yer make sure all youve good grounds (and make sure theyre all the same awg or thicker than your power wiring), upgrade the big 3, clean the power wire connections if theres any corrosion on em and see how you go from there

[euromandeluxe]

it rattles a little - i get my aeroscreen rattling against the roll hoop at certain frequencies which is pretty annoying. then again, i'm not pushing as much bass in my s2000 as some others are :p

thanks for the tips, i'll give them a shot.

i'm not sure if the battery is OEM as it's been changed out a few times by the previous owner - i'm not sure how many years the current one's been running either.

though this does remind me of from a few weeks ago (i think before these issues popped up?) that i've stupidly forgotten.

i found the battery was dead in the morning when i tried to start her up. jump started fine and let her run/took her for a long drive to try get the batt. back to charge, and it's seemed fine since then. however i noticed a LOT of powder over the negative terminal of the battery a few days ago. cleaned the terminal and ground loop up nice with a terminal cleaner and chucked some vaseline on, so that's sorted.

the battery read around 12.9V engine off and 14.7V engine idling while warm, which seems normal.

however today i noticed that all my interior lights are also dimming for a moment if i switch the a/c on or if i start to move the top (electric). will have to check if the same happens when i put my foot down on the brake with the engine off.

looks like maybe the battery's to blame? before i go out and buy a new one, are there any places that do battery tests (with the battery under load, etc)?

[2MPRS]

then its either ur alternator on the way or ur battery. easiest thing to do is start the car disconnect the battery if the car runs fine u know its not the alternator and its the battery, any auto electrician can check it for u. btw when u buy a new battery go and buy the most powerful one u can fit in the s2000 its a little bit more in price but saves u headaches later on

[euromandeluxe]

easiest thing to do is start the car disconnect the battery if the car runs fine u know its not the alternator and its the battery, any auto electrician can check it for u.

ahhh k. is it safe to do this? i read it can cause damage to the ECU and other electricals.

[2MPRS]

from what ive heard it should be ok just to disconnect it and test but ask others first

[euromandeluxe]

from what ive heard it should be ok just to disconnect it and test but ask others first

thanks. quick search found this:

http://www.troubleshooters.com/dont_disconnect_battery.htm

which sort of put me off. i did a few tests under load with the multimeter and it looks like the alternator's behaving, but i'll go to a proper auto shop to get it all tested anyway. hopefully it's just the battery.

thanks for all the tips :)