Voltage question

[teleman001]

I have the volt meter pulled up and noticed when I am off the accelerator it's at 14 V but when on the accelartor it drops down to 13. Eventually it goes to 12.....now and then. Doesn't sound normal to me as every other vehicle I have ever owned had a steady 14.2 - 14.3 charge rate. Is this normal for the S550's or do I have a regulator or alternator issue?

Sponsored

 

[PSI]

Totally normal, mine does the same thing.

 

[Angrey]

You can thank the EPA. The Ford BMS system is schyzo and it mostly has to do with economy (although there's other aspects that are battery life and alternator life). Just when you think you have it figured out, it'll do something different depending on RPM, state of the battery and current vehicle draw.

 

[teleman001]

Thanks for the replies!

 

[WItoTX]

If you want more info, search for the issue you mention. The question has been asked dozens of times, and lots of really good responses on here, as well as different scenarios, and what the voltage was showing, why it might be showing that, and what to look at in the future.

Welcome to the fire.

 

[Cole]

My 350 did that for about six months then the alternator failed, and Ford replaced it. Consistent now.

 

[engineermike]

Alternator voltage is controlled by the pcm and it’s a function of battery temp (which I believe is inferred) and fuel flow.

Sponsored