SM charging numbers?

[gusszgs]

Guys, what do you see for volts on the SM when cruising and hot?

I'm seeing 12.9-13.4 range. SM is 2.2 so quik update. Just a little concerned when taxing the system at WOT and the FP demands increase. FP is hotwired.

Is this acceptable or should I be seeing closer to 14 volts? Its just the factory alternator and a little long in the tooth. TIA

 

[Nick Micale]

Unless you have the Scanmaster ground running directly to the battery, you cannot have a valid number for measuring voltage.

Attaching the SM ground wire on the dash is not a proper place as the ground circuit there has a lot of resistance.

You also need to check voltage at the fuse block to assure proper voltage is present there as well.

I have seen voltage as low as 11.9v inside the car when the alt is showing 13.3v!

 

[Gene Van Horn]

Nick how does one go about correcting that problem?

 

[Nick Micale]

Nick how does one go about correcting that problem?

I "assume" you are asking about the interior low voltage issue?

In my 30 year old Limited, I was concerned about the XFI showing 11.9 - 12.3 voltage even at WOT.

Thanks to a good friend who has 40 years experience as a GM tech suggested to replace the ignition switch at the lower end of the column.

That $20 part gave me within .2-3 volts of the alt voltage at the fuse block!

I also ran a heavy gauge wire from the battery ground to the metal frame of the dash which may have also been a help too?

After messing with these cars for 30 years, I am very fortunate to have many "experts" that help me beyond my knowledge and experience to solve issues, as well as bring these cars into the 21st. Century!

 

[bad luck brick]

You're the chosen one.

Sent from my SM-G920V using Tapatalk

 

[gusszgs]

Thanks for the input Nick
So if I take a reading off the alternator and the volts are higher can I ignore the SM reading knowing that the hotwire kit is in place?

 

[Gene Van Horn]

Thanks Nick