Voltage Drop Question

[tckm]

Hey
I just got a volt meter and i was wondering if this happens when anyone else is driving

I noticed that at idle (in neutral, D4, D3, 2nd, or 1st) , my voltage was ~14
as soon as i step on the gas, it goes down to about 12.5

as soon as i reach ~3K rpm, it hops back up to ~14

and while im off the gas, its ~14, but as soon as im back on the gas, under 3K rpm, it goes back to 12V

is this normal or weird

i noticed it before too without the voltmeter (the lights dimming slightly when i was on the gas)

i have an aftermarket alt, and big 3

 

[Drift]

Its fine. During accel, the ecu turns "off" the alternator to save a bit of fuel while the energy is needed. When you get to the point that the ignition system needs the voltage, the ecu will kick the alternator back on. And during braking, its also on because because the brake lamps are on, requiring the extra voltage.

Ultimately, its all about emissions. If honda can get the tenth of a mile per gallon by changing the calibrations on the alternator, they'll do it!

 

[ryan s]

that is the great honda ELD in action

its been suggested that you turn on your headlights (well...OP is canadian so you have DRLs, right?)...also, some people are trying to add a mock load to the main fuse panel via a resistor network so the car never turns off the alternator.

no real success yet. the only proven method is getting rid of the USDM ecu, which isn't really an option in our cars. wonder if using an OBDI ecu would do it...?

 

[tckm]

damn, so its normal??

well i dont have drls because my hids deleted them somehow

i guess ill just have to live with it for now

thanks for the replies by the way

 

[ryan s]

yep, unfortunately normal.

does driving with the headlights on help at all?

 

[tckm]

i havent tried yet

ill let you guys know though in about an hour

 

[tckm]

just drove home with the lights on

stayed around 14v the whole way
no drops

 

[tckm]

just drove home with the lights on

stayed around 14v the whole way
no drops

edit
sh"t i accidentally posted this 2x

 

[ryan s]

interesting...well, it should work since the car "knows" about the headlight circuit. attaching stuff to the battery doesn't allow the car to notice the draw of the amps or accessories it seems.

what i really want to know is if DRLs help, only running at 40% brightness or whatever it is. i dont like driving with my headlights on during the day, but wouldn't mind DRLs. weird, i know

 

[tckm]

yeah i know its weird
will getting a new battery change this?
ill probably be getting the northstar nsb g2400 or something like it this summer either way

i could plug my regular headlights back in and let you know
ill do that on my way back to school