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Anyone have a 2018+ accord with a HO Alternator and had any success bypassing the ECU? I have 8500w+ system in my car and cant seem to get passed this stupid ECU controlling my voltage. I tried bypassing it with a alternator harness that wired to a sep 12v ign. Got great voltage, 14.8, but the car freaked out. lol. I am guessing i'll have to live with a 290a alter that is limited by the ECU.. for now. Just hoping someone had figured it out.
https://youtu.be/clN1mm_35-M
 

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Good day, I too have a 2018 Accord and was having voltage fluctuation. I did things like big 3 and battery swap and it didn’t help. By accident one day I was parked at night and turned my headlight’s off and happen to notice my Voltage dropped to 12.2, I then turned my headlight’s back on and the voltage went back up to 14.2 and stayed there as long as the headlights are on. Not sure why this happens but give it a try. I now drive with my headlight’s on when I want to get 14v.
Hope this can help
 

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Good day, I too have a 2018 Accord and was having voltage fluctuation. I did things like big 3 and battery swap and it didn’t help. By accident one day I was parked at night and turned my headlight’s off and happen to notice my Voltage dropped to 12.2, I then turned my headlight’s back on and the voltage went back up to 14.2 and stayed there as long as the headlights are on. Not sure why this happens but give it a try. I now drive with my headlight’s on when I want to get 14v.
Hope this can help
Hi, I plan on doing the Big 3 upgrade on my accord and was wondering how you went about to get to the alternator. I've looked everywhere and can't seem to find anything.
 

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Hi, I plan on doing the Big 3 upgrade on my accord and was wondering how you went about to get to the alternator. I've looked everywhere and can't seem to find anything.
I just picked up a custom unit from Auto Tech Engineering. They will build you one that can support your systems needs. What I'm wondering is whether I will need to run 1/0 Ga from Alt to Battery now with the increased current draw. Anyone have any ideas?
 

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There is no issue to fix. Making your dash lights come on cuz you bypassed your voltage will be an issue.

That said, what are you trying to do. Most amps run off of 14.4 or less which you can get by simply turning your lights on. If you got a beefier alternator you'll get your juice from there. 14.4 plus more amperage is all you need.

I'm running a total of 6k across 4 amps in my car on the stock alternator with hardly any voltage drop full tilt. I do have 2 lithums in the back and a AGM starter battery wich cost me more that a beefier alternator would have cost me.

But to answer your question there is no bypass. You would have to make your own. Which I highly suggest you don't.
 

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There is no issue to fix. Making your dash lights come on cuz you bypassed your voltage will be an issue.

That said, what are you trying to do. Most amps run off of 14.4 or less which you can get by simply turning your lights on. If you got a beefier alternator you'll get your juice from there. 14.4 plus more amperage is all you need.

I'm running a total of 6k across 4 amps in my car on the stock alternator with hardly any voltage drop full tilt. I do have 2 lithums in the back and a AGM starter battery wich cost me more that a beefier alternator would have cost me.

But to answer your question there is no bypass. You would have to make your own. Which I highly suggest you don't.
Thanks for the reply, I am trying to reduce voltage drop i have a 290 amp alternator, big three, but have a stock battery under the hood and a d4s lto 6.0 lithium in the back.
I am running a jp23 2300 watt rms on a x12 with a kicker 360rms. my voltage goes down to 10.5 lowest and sits at around 11.5 on full tilt. This is my first audio install ive been upgrading for over a year and wanted to know what i need to do to fix voltage drop.
 

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Those LTO lithium don't like high voltage and they are meant for discharge bursts, not reserve capacity. Get a good AGM starter battery, they are meant to hold more reserve capacity than the lithium you have. Get one of these.


Our stock batteries suck for car audio. That battery will help with the voltage drop. Your not running much power, you don't need to bypass your voltage regulator. You need to keep your voltage steady. When you turn the lights on it will jump to 14.4.

An other thing to consider is the type of wire you used. If you used CCA that will be your problem. It's best to always use OFC wire.
 
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