truck stutters when bass hits

soundnsecurity wrote: are your alternators internally regulated or do they have external regulator packs to control them? where did you tap for the field wire of the alternator for your audio?

I used the feed wire from the stock and jumped it to the other alternator.

oldspark wrote: If grounds are good and since disabling the audio alternator solves the problem, I'd suspect its purely mechanical and needs to be treated as if it's an aircon.

I don't understand

My money is on the load of the amplifier is taxing the alternator and just slowing the engine down. When you trip the breaker, the amp is still playing off of the battery. But it being not connected to the alternator, there is no load on that alternator, hence no decrease in RPM.

What I meant was as IAAI said - the load change is slowing the engine. Mere headlights can do the same and they may only be ~200W. But...

voltagexdt wrote: I used the feed wire from the stock and jumped it to the other alternator.

What "feed" wire? They should be separated. Each alternator should be sensing its own battery - ie, each Sense wire to battery +12V - they should nit be jumpered or shared. However if it's a single-wire alternator (D+) then there is no separate sense wire so that's not an issue. But each D+ or L charge-Light wire should have their own lamp else resistor in lieu. Connecting two D+/L circuits together can blow the regulators (D+/L outputs are usually GND else +12V - you do not want to short one to the other!),    

i am an idiot wrote: My money is on the load of the amplifier is taxing the alternator and just slowing the engine down. When you trip the breaker, the amp is still playing off of the battery. But it being not connected to the alternator, there is no load on that alternator, hence no decrease in RPM.

ok but how would it slow the engine down.

oldspark wrote: What I meant was as IAAI said - the load change is slowing the engine. Mere headlights can do the same and they may only be ~200W. But... voltagexdt wrote: I used the feed wire from the stock and jumped it to the other alternator. What "feed" wire? They should be separated. Each alternator should be sensing its own battery - ie, each Sense wire to battery +12V - they should nit be jumpered or shared. However if it's a single-wire alternator (D+) then there is no separate sense wire so that's not an issue. But each D+ or L charge-Light wire should have their own lamp else resistor in lieu. Connecting two D+/L circuits together can blow the regulators (D+/L outputs are usually GND else +12V - you do not want to short one to the other!),

the sense wire is a single wire that basically turns the alternator on I believe.. I contacted stinger on this and was instructed to simply jump from one sence of stock to the next.

I ask about the slowing the engine down because I thought of this, but then realized the engine spins the alt.. not visa versa. but I did question this.

I doubt very much that the 2 alternator wires should be shared UNLESS it is the IGN +12V feed, but few have that - especially these days. If it's the "battery sense" (S) or the charge lamp (D+ or L), they should definitely NOT be connected together. And obviously the main output (B/B+) isn't being shared. Only the GND is shared between separate alternator/battery circuits (plus IGN +12V if that is also required). If Stinger told you that - especially if they also told you the BC12 was suitable as a "dual battery isolator" - I'd be very wary, though maybe they do know what they are talking about in this case (it depends what that wire/circuit is).    As to slowing the engine down - electrical current is a load. A 110A alternator may take 2HP from the engine. At half output which is quite feasible at idle speeds, it's 1HP (~745W). As I said, if headlights under 200W (less than 1/4 HP) can dip an engine, then certainly so can a >1HP alternator.

oldspark wrote: I doubt very much that the 2 alternator wires should be shared UNLESS it is the IGN +12V feed, but few have that - especially these days. If it's the "battery sense" (S) or the charge lamp (D+ or L), they should definitely NOT be connected together. And obviously the main output (B/B+) isn't being shared. Only the GND is shared between separate alternator/battery circuits (plus IGN +12V if that is also required). If Stinger told you that - especially if they also told you the BC12 was suitable as a "dual battery isolator" - I'd be very wary, though maybe they do know what they are talking about in this case (it depends what that wire/circuit is).    As to slowing the engine down - electrical current is a load. A 110A alternator may take 2HP from the engine. At half output which is quite feasible at idle speeds, it's 1HP (~745W). As I said, if headlights under 200W (less than 1/4 HP) can dip an engine, then certainly so can a >1HP alternator.

Ok I did some research and numerous forums show that the field or excite wire needs to be connected to 12v switched. So I assume that's why stinger said to link between them

It does take horsepower in order to turn an alternator. With no load on the system, the alternator turns freely. With a load, it takes more power from the engine in order to turn it.