"I'd make ultra-sure you've got the wire pinouts correct.  You might need to use Mission Planner to gain access to the BRD_PWM_COUNT which could have possibility defaulted to something non-usable.  I don't think RELAY_PIN matters, but RCx_FUNCTION…"

"Flight Report ArduCopter-3.2-rc6

Hardware: 3DR 2013 Y6B with Pixhawk, Tarot-T2D Gimbal, 3DR uBlox GPS / Compass
3S and 4S batteries

This is a delayed report of more testing against ArduCopter-3.2-rc6 from over the weekend.
I ran AUTO, DRIFT,…"

"It's not clear if you're using the Tarot gimbal controller or not.
Two things I was reminded of when upgrading to AC3.2-rc6

Make sure the blue light on the Tarot Control board is flashing (it's receiving external commanding)
Make sure…"

"Flight Report ArduCopter-3.2-rc6

Hardware: 3DR 2013 Y6B with Pixhawk, Tarot-T2D Gimbal, 3DR uBlox GPS / Compass
3S and 4S batteries
EKF disabled 

Takeoffs and landings in stabilize, alt hold, loiter and pos hold.  Everything looks great!  Position…"

"Spektrum DX7s"

"Solved!
It turns out if you've ever clicked on "Point Camera Here" in APM Planner, it will do something like a "Do-Set-ROI" which changes the value of the parameter MNT_MODE = 2 (MavLink_targeting), with the result being that it will forever ignore…"

"Mine does level and track horizon without the wires hooking it to the Pixhawk.

If I connect it to the pixhawk, I can crudely adjust it by changing the Gimbal parameters, but alas not with the AUX knob yet."

"So far as I can tell, this is all that needs to be done.  You can "enable motors" to see it point straight and level, and perhaps you may need to "save settings to flash" after done."

"I - I've performed the calibration a few times over having it set up.  Camera on its back, pointing at the sky and as "level" as I can make it.  After the calibration is looks like its reading zeros on pitch/tilt/roll when the camera is pointing…"

"I'm having similar problems controlling tilt on my Tarot-2D, and at a loss of what to try next.
Here's what I've done so far:

Followed all the instructions on the wiki
Verified that Signal (AUX 1 / RC9 on the Pixhawk) and ground are in the right…"

"From what I can see in the picture, that looks like a 3D printed mount adapter.  Can you share the STL file?"