Voltage fluctuations 2011 3.8 , alternator or?

[LS400reincarnated]

Hello everyone
Long time no post, does anyone drive with a little USB charger that shows voltage?

I Connected my trusty old OBD scanner today just to monitor coolant temps and what not

Everything looked good until I saw voltage drop from 14.1 to 12 when accelerating from a stop.

Happens every time. I then parked put the car in neutral, revved it hard , drops from 14.1 volts to 12 or so.

Slowly gets back up to 14.1 in a few seconds but then every time you give it hard throttle it dips to 12v...

Today Im driving on the highway, and Everytime I give it more than 15 percent throttle I see the voltage going down until I let off. Doesn't make any logical sense, belt is not loose. Voltage regulator and therefore I need a new alternator or did others notice that too and cars remains fine?

Thanks

 

[EdP]

Today Im driving on the highway, and Everytime I give it more than 15 percent throttle I see the voltage going down until I let off. Doesn't make any logical sense, belt is not loose. Voltage regulator and therefore I need a new alternator or did others notice that too and cars remains fine?

Thanks

It actually makes logical sense to me. Unlike cars of the past, computers sense and control a lot of functions and conditions. It takes power from the engine to turn the alternator and it takes more when charging than just idling at full charge. My theory is the computer sees you accelerating and says, "hey, give this guy all the engine power he wants, hold the alternator"

Just my theory, probably someone here knows more of the details how new systems work.

 

[LS400reincarnated]

It actually makes logical sense to me. Unlike cars of the past, computers sense and control a lot of functions and conditions. It takes power from the engine to turn the alternator and it takes more when charging than just idling at full charge. My theory is the computer sees you accelerating and says, "hey, give this guy all the engine power he wants, hold the alternator"

Just my theory, probably someone here knows more of the details how new systems work.

I was playing with a similar idea, because car seems to perform just fine, someone on 1st gen group on FB with one of those USB chargers with voltage monitor said his car is acting exactly the same. However I cant see frequent 2 sometimes 2+ volt fluctuations being good the battery but who knows. Was wondering if anyone else ever monitored or can check voltage using an OBD2 scanner to see how other first gens act. In most ways Genesis used well known older technological solutions, not too many innovations, so I was expecting this charging system to act the same as any typical charging system

 

[LS400reincarnated]

Will be buying a refurbished Denso alternator today and installing it at the end of the week. However if anyone can let me know if their Genesis is experiencing similar behavior please let me know

 

[LS400reincarnated]

Ah I wish someone else with either an OBD scanner plugged in or even with the charger with voltage meter plugged in could tell me if it's indeed by design or because alternator is beginning to fail. Will be installing new alternator tomorrow possibly for nothing lol, EdP might be correct as I did find that old Isuzu troopers have that as a feature to decrease load on the engine when accelerating.

 

[LS400reincarnated]

For anyone interested I did replace the alternator with a refurb Denso unit and a OEM serpentine belt. Voltage drops are still there. So either the car some similar to ELD system, where it turns off alternator under load to allow for better fuel efficiency/"mo powa"

Or my issue lies elsewhere. Too bad the forum is dead and noone can test their car the same way. Hopefully this will help someone in the future

 

[j_fields1357]

For anyone interested I did replace the alternator with a refurb Denso unit and a OEM serpentine belt. Voltage drops are still there. So either the car some similar to ELD system, where it turns off alternator under load to allow for better fuel efficiency/"mo powa"

Or my issue lies elsewhere. Too bad the forum is dead and noone can test their car the same way. Hopefully this will help someone in the future

My Gen 1 does exactly the same thing. When i give more than light throttle from a stop it dips from 14.3 to into the 12s. I just recently purchased a 350 amp alternator since i have quite the system in the trunk!