alt issue

hardtymermiata · Post by **hardtymermiata** » Mon Apr 26, 2010 8:12 am

not sure if is the right place but when driving at night i've got a flashing headlight issue . i've read about the BIG 3 thinking about trying it . but could haveing the internals of my alt upgraded also help . my car is an '02 miata from what i've found out the alt only puts out 90 amps .

Bwcad1 · Post by **Bwcad1** » Mon Apr 26, 2010 8:21 am

hardtymermiata wrote:not sure if is the right place but when driving at night i've got a flashing headlight issue . i've read about the BIG 3 thinking about trying it . but could haveing the internals of my alt upgraded also help . my car is an '02 miata from what i've found out the alt only puts out 90 amps .

It could but lets see if we can find a cheaper alternative first.

What does your stereo consist of?

Ryan from Ohio · Post by **Ryan from Ohio** » Mon Apr 26, 2010 8:26 am

Perfect place for the topic.

As Bill stated, we will need to know what all is in the vehicle and what size wiring you have.

hardtymermiata · Post by **hardtymermiata** » Mon Apr 26, 2010 8:32 am

not a prob . two 12" PPI PCX124 , ARC FD 600.1 , ARC FD 4150 headunit is a PIONEER AVH-P4000DVD I've got a KINETIK HC600 and a POWER ACOUSTIK 2farad cap . useing 4 gauge power and ground wire .

Bwcad1 · Post by **Bwcad1** » Mon Apr 26, 2010 8:36 am

I would upgrade the Big 3 then change out your main starting battery to something a bit larger. Your not drawing enough to warrant an alternator at this point IMO.

hardtymermiata · Post by **hardtymermiata** » Mon Apr 26, 2010 8:40 am

ok thinks what size wire would you say that i use for the Big 3

Bwcad1 · Post by **Bwcad1** » Mon Apr 26, 2010 8:53 am

4ga is plenty.

Post by **GlassWolf** » Mon Apr 26, 2010 8:56 am

could be a few things.
insufficient current from the alternator to drive the amplifiers - need to upgrade the alternator to a high output or rewound alternator.

may need to do the "big 3" (required with a HO alternator anyway) to see if the amplifiers are causing more current draw than the factory wiring can sustain. (helpful but rarely fixes the whole problem.)

lastly, alternators are relatively slow to respond to spikes in current demand, so when bass hits, it can take the alternator a moment to respond to that demand. This can cause dimming lights without really being an issue of the alternator's inability to supply hte needed current. It these instances a capacitor or two can assist in response time from the alternator, but this is really the only time a capacitor does much good. The problem with a cap is that if the alternator is insufficient for current demands, the cap can mask these symptoms, and allow the system to play without lights dimming by smoothing out the sudden drops in voltage. The problem here is the result is that your voltage rails will remain below where they need to be instead of just dropping momentarily. The only way to relly know is to monitor your voltages both at idle, and above idle to see what the response is over a period of time.

hardtymermiata · Post by **hardtymermiata** » Mon Apr 26, 2010 8:59 am

thanks again . i've put it on a SPL meter once and got a 136.9 to 137 db . not great but not comp worthy but hey it a soft top . besides that i'd be competeing angainst my wife , and i wouldn't stand a chance .

Post by **GlassWolf** » Mon Apr 26, 2010 9:08 am

eh, SPL isn't everything. Personally I'm more interested in how good it sounds rather tahn how quickly I'll need haring aides as I get older.