Stall Horn Location M20J

[Txbyker]

I have an '87 M20J and am trying to find out which horn is the stall horn as it currently is not working.  I think the shop missed it on my pre-buy.  The horns are relatively inexpensive so I figured I would just replace the Mallory SC628 horn and at least take that out of the equation.  Can anyone tell me how I can identify the stall horn?

Thanks,

Russ

[Piloto]

Set the stall vane switch in the up position with tape.

Remove the right speaker grill and the sonalerts bracket.

Set the master ON

Measure the voltage at the sonalerts.

Whichever is getting voltage is the stall one.

Remove the sonalert and knock it into a hard surface. Half the time it will fix itself.

José

 

[Txbyker]

Great idea thanks.  Right speaker grill.  I have 3 sonalerts there and will check them.

 

Thanks!

[KSMooniac]

It could also be corrosion on the stall vane microswitch.  You might spray some electrical contact cleaner into the switch from the wing inspection panel and exercise the switch repeatedly.