power system setup ?

[ncc74656 2]

i unplugged my sub yesterday and noticed that running my mids/high amps cause my lights to dimm very slightly when bass hits. when an amp draws power it is producing a spike draw on the entire vehicles system wich it is not designed for as there really is nothing else on a car that will pull such a bust draw outside of cranking. how common is it to see a slight dimming of lights on audio installs? i ask because to me it seems that with 2 large batteries and a HO alt i would expect not to see any dimming regardless of volume level.  now the wiring is good and i am certain that all my grounds/contacts are properly terminated.  i am looking more into this as I am planing to add a great deal of extra draw on my electrical and id like some thoughts on what im looking to do. My understanding is that such a setup is used in competition but not so much in daily drivers.

 

My thought is to make 2 separate electrical systems. take the factory alt/batteries and leave them as is with no after market audio hooked ot this outside of the head unit itself (or perhaps the head unit should also be on the same circuit as the amps?). Take my 320 mechman and upgrade it to there 400+ model (i was told my a local starter/alt rebuild shop that anyone who claims an alt for my vehicle is putting out more than 210A is lying there ass off as it is not physically possible to go beyond that, I intend to bench test my mechman to see if it is truly doing rated power) assuming it is worth it of course and moving my current agm batteries to the back. hooking the after market alt and 2 agm batteries directly to one another with an external voltage regulator and then hooking all my amps to those 2 batteries. i would simply add 2 cheap lead acid batteries under the hood to use for normal vehicle stuff.  now would i still want to ground out to the frame OR would it be preferred to run dedicated wires for ground to the alt and amps making sure to isolate the alt from grounding to the rest of the truck? basically is it a bad thing to mix 2 independent electrical systems grounds?

 

my thought is that i could then have a dedicated set of batteries to power my audio and i could ensure no ill effects due to voltage drops or spikes on the rest of my truck. additionally i could also go up to a 15 or 16v system quite easily in the future if i chose to do so.

 

open to thoughts and recommendations, thanks.

[ssh 924]

Yes light dimming is common in car audio.

Lights dim due to a sudden change in voltage. Whether that change is from 15.015v to 14.12v, or 14.5v to 11.84v. So the dimming alone doesn't necessarily mean you need more power. Check your voltage at idle and with the system at full tilt.

 

If it's your headlights dimming you could switch to an HID system with a ballast, I don't believe voltage fluctuation will affect them.

If it's your interior lights then I'm not sure what would be a good way to alleviate it. Moving a battery to the rear near the amp might help, but I'm not entirely sure.

[ncc74656 2]

i do have 55W hids and they are fine. the lights dimm quite drastically in the cab when my sub is full tilt however i also am pulling power with a 2500W kicker, a 800W eclipse, and a 300W audiobahn (rough numbers) while driving down the road and 90% of my driving time is spent with the system at <95% volume. i am currently planing to add a second 2500W kicker and perhaps a second 18" sub (2 Fi team 18's) so i was thinking it may be time to just build up a second dedicated power system.  

 

i do not believe the current PCM runs the alt at full tilt for more than a 40% duty cycle (per my repair manual) so i was thinking switching to an external voltage regulator would be greatly beneficial. 

 

i have been reading into conductivity of 1/8" mild steel and question if i should have the batteries under the truck with in 1' of a grounding block for the amps so as to allow me to ground directly to the batteries vs to the frame. is it possible that my frame acting as the grounding point is the issue given the large power draws i am pushing?

Edited January 24, 2014 by ncc74656

[Randal Johnson 544]

Sounds like you need to invest in a Battery Bank for the rear of your vehicle With adequate wiring and charging power ...

One battery up front with atleast 3 to 4 batteries near the amplifiers ...

Take a look a DangRebel's (Clint) setup ...

[Dexter Chaos 14]

You haven't stated you whether you have the big3 done. Just want to check. This helps As well

[///M5 2,833]

Cheap ass headlight conversions suck. Bet with normal bulbs you wouldn't be seeing a problem. You'd probably have better headlights too. Take the rice out and be happy.

[ssh 924]

Cheap ass headlight conversions suck. Bet with normal bulbs you wouldn't be seeing a problem. You'd probably have better headlights too. Take the rice out and be happy.

He just said they don't dim, the interior lights dim.

[ncc74656 2]

my HID's are american made, got them for about 300.00 and they work very well, i am quite happy with them. a friend has some Hids in his car and they are no where near as bright as mine.   it is my interior lights that dimm, i would say the gauge cluster and after market gauges dimm as if they go from 14V down to about 7V. i am gauging this based on intensity of light and not by a meter but its quite noticeable. with out the sub on i only see a small flicker. 

[Tirefryr 1,742]

You need to determine where the voltage drop is happening.  I don't know the vehicle or how it's wired, but it could have an issue with a lighting controller, a switch if all current runs through it, a simple relay, or something as simple as old lamps.  As they age, they draw more current (incandescents).  There are so many factors that could be an issue here and you want to determine the cause before you can fix it. 

I won't say why, but I am not a fan of aftermarket alternators on with computer controlled regulation.

[j-roadtatts 1,129]

A dedicated charging system will work great to by pass the PCM if that is your purpose. As far as ground, It will not matter with a DC system. Save some wire.

[j-roadtatts 1,129]

You will need a one wire alternator or a 12 volt exciter wire.

[ncc74656 2]

my understanding of the external voltage regulator from mechman is that it controls the alt's charging all by itself (exciter wire included). would this regulator be capable of determining when its over charging the batteries and cut out or would it just stay on at what ever voltage setting 100% of the time?

[Tirefryr 1,742]

It will regulate due to current demands just like any regulator.