I bought a Simoniz Pressure 1400 psi washer 2 years ago, it has been
working fine until recently. The problem is, after I turn it on the motor
cannot stop although the water comes out with the right pressure. The motor
is supposed to stop when releasing the trigger, but it doesn't. EVEN WORSE,
when I switch the unit to OFF position, the motor is still running!!! It
seems like a bad design because the power switch doesn't even kill the
incoming 110V !! So, I had to pull the plug in order to stop it.

My friend is having the same model , and has exactly the same problem.
Anyone knows how to fix it?