Not much info to go on...
Jim, only "button" I can think of is the Auto Pilot override. Is it red in color?
Here is the info I found....F-1291 ROLL SERVO PUSHROD IF DYNON AP SV32 AUTOPILOT (ROLL) SERVO WH-00049 AUTOPILOT DISCONNECT ... 00007 WH-00025 WH-00049 ES-00008 ES ... Install the WH-00049 Autopilot Disconnect
vansaircraft.com/pdf/revisions/RV-12/Section_44A.pdf