stall warning inop on m20c.

[billy hellcat]

My stall warning isn't working.  Any ideas?  Thanks

[Rmfriday]

Check the sounder itself. Mine went bad a couple of months ago and lasar had the part in stock. It is on the co-pilot side up high. If you still have the original avionics access  it will be easy to get at and confirm that is the problem, if you have the lasar 201 windshield mod it might be tricky. I have the SWA windshield mod so I retain a small access panel, it wasn’t to bad. Get your hands on the wiring diagram to trouble shoot, it’s a simple system, when the “stall flap” is up it completes the system and the horn sounds. 

[EricJ]

If it's a sonalert in the overhead, they're simple and cheap to replace.  You can buy them online from many places; they're not PMA.  They're easy to test with the master switch on by grounding the non-powered terminal.

If the sonalert works it's either the wiring to the vane switch or the switch itself.    All the switch does is ground the non-powered side of the sonalert to complete the circuit.   The switch and wiring can be tested with a multimeter at the non-powered side of the sonalert to see if it shorts to ground when the vane switch is closed.    If it doesn't, then test the switch electrically, which is a little tricky just because it is difficult to access.

 

[Hank]

Make the "D'oh!" check.and make sure the breaker is tripped. When I moved, I found an IA ti do the annual and he washed the plane right before I arrived to pick it up. As soon as I flipped the Master Switch, there was an annoying, loud buzz. He checked and said it was the stall horn, because he didn't cover the static ports when washing, and his fix wasn't to drain the line but to pull the breaker. Never went back to him . . . .

[Nico1]

+1 sonalert, they go bad all the time