charging

[MAJpo20]

In a 2003 Ford Taurus, 3.0 SOC, does anyone know the reading of voltage from the PCM to alternator control circuit? Keep blowing alternators and everything else seems to be checking out. Been told that computer controls alternator and that is a variable voltage but need to know the range. Thanks

[shorod]

Originally Posted by MAJpo20

In a 2003 Ford Taurus, 3.0 SOC, does anyone know the reading of voltage from the PCM to alternator control circuit? Keep blowing alternators and everything else seems to be checking out. Been told that computer controls alternator and that is a variable voltage but need to know the range. Thanks

The line you are referring to is the GenCom wire between the voltage regulator and the PCM. It should be a light blue wire with a red tracer. With the key in the RUN position and the engine off, there should be between 1 and 3 Vdc on this wire. With the engine running, the voltage on the GenCom line should be 13 to 15 Vdc. With the key off, there should be no voltage on this line.

You don't happen to have a large stereo system in your car or something else that would be drawing large amounts of continuous current, do you?

-Rod

[MarkHutch]

Originally Posted by shorod

You don't happen to have a large stereo system in your car or something else that would be drawing large amounts of continuous current, do you?

-Rod

I was wondering if something like this could be cause by running extra equipment like TV's and VCR via the electronic power points in the vehicle? I know these devices run fine in vans, but they may have stonger electrical equipment.