I've had the 3S for a week and they seem to record about 40% of my ride. The rest of the time they don't respond at all or give insane power spikes. They have been tried on both my bikes with similar results. The pedals are now back in their box. Before I return them, is there hope for this?
What is the rest of your system setup? Are you using an Edge or Forerunner or another different bike computer? If you have your 3S linked to your phone, try removing it from the phone.
I use the Edge 520 and I've removed the pedals from my GCM devices on my iPhone. I've removed the battery cap to restart the system and it always works initially. Thanks for you quick response.