Valeo Voltage regulator output voltage

[Vinny187]

Hi Guys , I'm looking for information on how to adjust the internal voltage regulator on a 2009 passat with a valeo 180amp alternator. I've found plenty information on other branded alternators but hardly anything on valeo ,Or i would even appreciate information on how this specific alternator adjusts the voltage so I can manipulate the readings it gets.

[MIG]

Hi and welcome

Being a 2009 I think that was right on the cutover with the DFM and LIN alternators, in your installation list do you have "Address 61: Battery Regul. (J840)" ?

If it is the LIN version, the brands have a standard coms protocol.

[Vinny187]

Thanx for the welcome Mate .. but Nah not LIN , it's DFM and L . There must be a way to internally manipulate the regulator... but I've been searching for days and haven't found solid info. Plenty on Bosch and Denso , But almost nothing on Valeo.

[MIG]

Are you trying to increase the voltage at idle or something? or is it not outputting the correct voltage?

As it's an internally regulated alternator, you can sometimes open it and get to the connection used by the regulator reference. Adding a diode between these will cause a voltage drop to the regulator, making it output more to compensate.