STEC-30 Issue

[Pa28-140]

I have an SEC-30 autopilot in my Cherokee 140. It's been pretty bulletproof but developed an issue today that I was hoping someone could give me some insight on.

I do not have electric trim. So, the trim up/down light and aural alert come on when the altitude hold needs a little trim help for me to do it manually. Today, the "trim up" light and aural alert came on……but stays on no matter what the trim configuration. The altitude hold works fine, just the constant "trim up" warning. Turning the system on/off did no good. When I got on the ground, I turned they autopilot on and got the constant light/beeping even on the ground. Any thoughts on what this might be and what it might take to fix?

Thanks in advance for any replies.

 

[Tj1376]

Doesn't the stec 30 have a motor and pressure sensor that control the altitude hold. Thus it moves the yoke and not the trim to control (and hence why you need the lights.) if so, I'd take a peak at the wires to the sensor and troubleshoot the sensor.

TJ


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[DesertNomad]

I have the same autopilot and electric trim on my Dakota and it still asks me to trim when needed... but I do it with electric trim. It is supposed to do this by itself? I certainly do not notice the yoke moving.

 

[SCCutler]

The trim warning comes from excessive current required to the pitch servo to hold altitude. Could be the servo, or the computer.

I bet your avionics shop would love to help!

 

[Brad Z]

Could be a bunch of things, and the avionics shop is going to be the best answer here, unfortunately.