The oem solid state flashers are a pretty high failure item, and this design has the flasher pulsing 100% of the time. Y0u can disconnect it(under passenger dash) and put a jumper across pin A-B which, if power is available on pin A, will send power thru the rest of the circuit for testing. I replaced mine with a commercial 12A unit made by grote…
The only thing that clicks in the signal circuit are K30 and 31, but these are for 24v trailer power and no-one I know has a 24v commercial semi-trailer. K06 and K10 should go click when you step on the brake pedal(must be air in the tanks to activate the pressure switches on the treadle valve…