So im using a mosfet as a switch to supply power to a servo, move the servo, then switch off. I have the pins wired as follows:
Gate: to pin 9 Drain: to negative of servo Source: to negative of 6v AA battery pack.
I have a resistor that starts at the gate and connects to source. source is also grounded.
When the mosfet is turned on it has a voltage across G/S of about 50mV. When its turned off there is a 4v across the two pins. the servo sees 2v across +/- when the mosfet is off. pin 9 has 0v when its supposed to be off so it is turning off.
EDIT: when i unplug the servo the voltage goes to 0.
Everything works as expected though but its important to have the mosfet off when not in use so that the batteries are saved.