S-Tec documentation

Hi all,

I'm trying to debug a problem with my S-Tec system 30 autopilot, but I bought the airplane built and with autopilot already installed, and there is no documentation. Does anyone have something they could share, maybe a wiring diagram?

Just in case, the problem is that in the heading mode, the autopilot steers 10-15 degrees to the right of the heading bug. Everything else works just fine, including GPSS and NAV mode. I've tested the DG (I have a 52D54), and it appears to work just fine. I assume the problem is in the GPSS module, but without documentation it is hard to figure out what to do next.

Any help or ideas would be appreciated.

P.S: I don't yet have time to commit to upgrading the panel, but eventually I'll get rid of this AP.

You'll have better luck on one of the certified aircraft forums where the STEC A/P is commonly installed. Putting one in an experimental is not typical due to cost.

I accidentally found this, so posting it for whoever may need it in the future (unlikely): http://www.csobeech.com/files/STec30-Install.pdf

Turns out the installer wired lighting dimmer to one of the heading inputs of the roll steering converter.