i have narrowed a parasitic drain down to the number 11 alternator field fuse in my 2001 Ford F150 lariot 5.4 fuse box.
i cant seem to find much information about this. any suggestions to what could be causing this and how to fix it.
My battery is new and my alternator is charging my battery as normal. i recently put in a starter and my odometer doesnt light up anymore. any help would be greatly appreciated. thanks, Aaron

 

The Field winding is supplied voltage from the battery through a fuse #11.
This voltage controls the current output from the alternator back to back to the battery.
The circuit has to go through the regulator so it can control output level.
If there is drain with the motor off suspect the regulator having a fault.
To get more specific, the regulator has a reference circuit that is used to compare the battery voltage to the reference.
The difference is what controls the field voltage hence the current output to the battery.
As the difference gets smaller the charge current goes down until the battery float level and the vehicle requirements are met.
After starting the battery voltage goes down. The reference detects this and raises the alternator output and the voltage.
As the battery voltage recovers the regulator reduces the voltage to the field winding until the system comes to balance for the load it has to serve.
The load changes as you use such functions as the Heater Fan, headlights etc.
Then the regulator automatically make continuous changes to meet the demand.
After the battery is up to float, the vehicle is powered from the alternator almost 100%.

Good luck.