FET issue

I have a BUZ101S FET rated for 55 Volts 20 or so amps (max ratings). I want to drive a 12 volt motor from a battery with it. My FET is not responding the way I want it to... is this fet still a 5V at the gate?

My FET is not responding the way I want it to.

Can you provide your schematics? It will be a lot easier for us to help you.

My FET is not responding the way I want it to

Umm... could you be a bit more specific?

is this fet still a 5V at the gate?

That MOSFET is simply not a LOGIC level device. +5vdc will not fully turn on the device and thus will dissipate too much heat instead.

Lefty

So you need to either change the FET or drive the gate with a 12V signal. To drive it with a 12V signal you will need a transistor. Arduino output to a 1K resistor, other end of resistor to the base. Emitter to ground and collector to FET gate. Then put a 3K resistor between the gate and the +12v. make sure the FETs source is also connected to ground and your motor is connected to the drain, with the other end to +12V.