I have just bought a used 382 formula and I can't seem to get the macerator to work! I tryed turning on the power and hitting the switch, but it just kicks the breaker. Im not sure but I thought there is only the Y valve in the back that can obstuct the flow or am I missing something or not doing something wrong!!!
Better yet is there any way to test the unit or see if its clogged?
Im totally lost with the macerator!

Yes it is open

Can you hear it running when you push the button in the head?

No !!! There is no noise at all , when you push the button!!

The impeller is probably bad, I'm pretty sure they still use a jabsco macerator, you can but a impeller kit, pretty easy to do other than getting to the unit to get it out.

If it's kicking the breaker off when you push the button, it sounds like the motor is seized.

The motor seal has let doody water get in the front bushing and it has seized the armature. A rebuild kit will contain all your necessary parts.