Voltage terminal 30

[AngelA5]

hi everyone, sorry for my bad english.
I noticed that the "terminal 30" with the car on and the passenger compartment air fans on, shows 11.9V.
The battery is new and correctly coded.
Could it be the 643 relay?
if I'm not mistaken the voltage should be about 14v?
any suggestions?

 

[NHN]

14v when charging, not when standing.

Between 12 to 13v static ignition of.

Could be a faulty ignition switch, slot in dash, that's not switching of when key removed, they can be finicky, hypothetical as I'm not working on the car directly.

 

[Dippy]

If "with the car on" you are referring to the electrical system status and not the engine then with no external charging the maximum you should see would be 12.6V which is the open-circuit resting potential from a new battery of typical cell configuration (they can be overcharged to slightly more but will fall back to 12.6V). With electrical loads this will drop as the battery is discharged and the fans are high load. If the battery was fully charged (note that in cars using stop/start and with no external charging the battery rarely has full charge unless after a long journey) then I'd say the fans should have been running for a long time for it to fall to 11.9V. The best way to check is to measure directly at the terminals in the engine bay with the doors closed and after all the lights have extinguished - see what it settles at.