Phoenix Gold Phorum

I have a 300 amp secondary alternator. It is externally regulated and that is going to a Stinger battery. This system is feeding only my two amps. Everything else is powered by the OEM alternator and battery.

The voltage on the RMD is around 12.7 At idle most of the time, but if I am going down the road at 60mph it will go up to 14.6. However if I turn the system up it quickly drops. Even with the system volume at 0, if I slow down and stop the voltage quickly plummets. This all started recently. Until about a week ago the voltage was rock solid at idle with the system up, and all other times too of course. Now I can't even slow down with no power load without it dropping.

I unhooked the battery terminals and hooked up a microprocessor controlled battery charger to it, and it instantly showed the battery as being 95% charged.

Just about has to be the voltage regulator doesn't it? That or the PG voltage gauge I guess....... The fact that the battery is at 95% just about rules out the alternator and battery doesn't it? Could it be anything else?

I''m gonna guess either a voltage regulator or a bad voltage gauge

Start simple - Check your grounds. By check I mean disconnect/clean and then reconnect them and see if its any different afterwards.

try to eliminate all possiblities, get a volt meter and hook it up directly to your battery. now if possible run your car on road and watch the voltage.


see if it stays rock solid, if it does then your problem is not as bad as you expected.

if the voltage still takes a dive i am gonna agree with ttocs and you may want to check all connections to that alternator. also check the voltage sensing wire to make sure its connection is clean and solid.

if all good then take it to a shop with a VAT 40 and do a load test on the alternator itself to see if the regulator is bad.

good luck

The VR is what first came to mind to me too.

I forgot to mention that I also have a voltage meter on the battery post that pretty much stays within .15 And .20 Of what the PG voltage meter is reading. It has always been a little lower, and I blame it on a calibration difference. The fact that they both track together kind of eliminates the gauge being an issue.

I am getting a new regulator put in next week (First chance I have because of work), and upgrading to a Stinger SPP2250 battery while I'm at it for good measure. The connections will be checked/cleaned at this time also. I figure if this doesn't solve it I'll be upgrading alternators.

Out of curiosity, is there any behavior from the user that can put excess strain on a regulator causing it to fail, or is it just one of those things that happens?

I was told by the old guy that rebuilt my alt that they just do not last long when you go into a HO alt. Said that its just part of the beast that they go through alt/brushes/regulators more often just because of the use.

Hopefully there isn't a bigger problem causing it to fail though.

ttocs wrote: Hopefully there isn't a bigger problem causing it to fail though.

I halfway suspect that the battery might be an issue. Right now I have a Stinger SPP1200 which is a hold over from when I was running just an Elite.5. Stinger's website says that battery is only recommended for systems under 2000 watts. Now that I am running an Elite.1 and Elite.4 I'm pushing damn near twice that, so I am going to go up to the SPP2250 (if it'll fit in my battery tray. I think it will) which is recommended for 5000+ watts. That's why I am going ahead and doing the battery too.

Seems like the regulators are the weak link in the whole thing though. Granted, they are the cheapest part compared to the alts and batteries, but it isn't like an external regulator has to fit into an OEM location like alts and batts either. You'd think someone would come up with a way to make them more rugged for HO applications, even at the expense of making them somewhat bigger.

my only question is what do you listen to? if its music then i think at this point your not doing anything wrong. being that music is dynamic you would only be pulling that amount of current if you peaks are that high.

i really dont think you are outputing 5k all the time. i think you may have an issue with voltage regulator.
also you may want to check belt tension if applicable. it may be slipping on hard amperage draws causing you to lose voltage. once you load test it then you will know if its regualtor or not. if it passes load test ( i mean take it out of car and take it to a place that can test it), then you may have a bad connection in your car that is being overlooked. i seriously would check all voltage sensncing wires to the regulator. is this externally regulated alternator? sometimes the plugs and adapters may have a bad or loose connection causing the concerns you have. let us know if you once you test it.

the reason i suggest the check is i 16 years ago had a 87 nissan sentra with a 225 alternator and it would drop like mad. i checked everything and all was good. then one day i decided to just run a new wire from battery to the regulator sence wire and bam it was fixed. so i dicected the stock wire that plugged into my alternator and it was corroded.

aloha.

90% of the time I listen to rock and metal, and the rest of the time it is bass heavy electronic type music. No sine waves or anything like that. The sub amp is rated at 2800 rms, but where my subs are in a sealed enclosure, I very seriously doubt I am even pulling that much on the hardest of bass tracks. I'd say it's closer to 2000 watts at best on the subs. The four channel is running at 2 ohms roughly 300 watts per channel in the front, and four ohms, 200 watts per channel in the rear (rated 150 at 4 ohm, 250 at 2 ohm, but the birth sheet is higher), so the four channel is making close to 1000 watts itself.

One thing is that for me this car audio system is like wiping my butt with a wagon wheel. It never ends. I'm probably going to expand it a bit in the spring, perhaps adding another Elite.4 and either add another Elite.1 or just drop the one I have down to 1 ohm, so upgrading the battery is partially to help with what I have now, but mostly to lay groundwork for what I might do later.