Stall indicator on a '74F

[aerobat95]

Hey guys, quick question for you.  Can you test the stall indicator on the ground with the engine off?  I am assuming you can.  Today I was going over my plane and when I actuated the switch.....I didnt hear anything.  Any ideas??  Oh and yes the master and avionics master were both on. 

[Lionudakis]

Engine shouldn't have anything to do with it. Any I've messed with is right off the master sw, mine is. 

[1964-M20E]

You should be able to turn on the master switch move the stall switch and you sould hear the horn.  If not something may be wrong.

[philipneeper]

on my 78 C, i have the master switch on and i can move the tab located on left wing and mine activates

[DaV8or]

It's part of my preflight every time. Master on, walk around and check lights and check stall tab. Flip it up and the horn should sound. If it doesn't, you have a problem.

[aerobat95]

Thanks for the input....kinda what I was thinking.  Any ideas where the problem might be?  Does that have a direct input to the speaker?  I wonder if it came loose.

[Ned Gravel]

Raymond:

If yours is like mine, that speaker is behind the panel somewhere.  

[Bartman]

I had a problem once and we discovered that there are two horn speakers in the overhead trim. One for the stall horn and one for the gear. The switch is simple on/off and easily tested.

We ended up cleaning the speakers without success. I now have a new stall horn switch in the wing, but it needs adjustment. If they replace your switch please make sure they tighten the screws such that it is in the middle of its travel for adjustment. Mine is at the bottom of the adjustment and won't activate until it is very close to stall.

[DrBill]

Same switch as my Beech. I had same problem.  Was very fine dust causing the plunger in the switch. I replaced the switch (not cheap) and then did failure analysis. I could see that the plunger did not come out so we (A&P and I) used compressed air on it to clean it out.  Lubed it up with silicone spray and it's like new.

Took about 30 mins.

BILL

 

[KSMooniac]

Most likely failure is the microswitch behind the stall warning vane.  You can contort your arm inside that bay with a mirror, light and some contact cleaner (aerosol spray from Radio Shack or similar).  Give it a liberal cleaning and blow/dry it out with some electronics cleaner (also an aerosol spray) and hopefully it will start working again.