My new Vector 3 pedals are quite stiff compared with my Vector 2 pedals, especially the right hand pedal. The RH pedal is so stiff that it doesn't spin relative to the crank, when I spin the crank. The LH one is a bit better. Will they loosen up with time or is this what everyone is experiencing with these pedals?
The seals on the Vector 3 pedals have more static friction than the seals on the Vector 2 pedals. Once the pedals are rotating that friction becomes negligible, and over time they do wear in a bit so that the pedals will freely rotate heel-down from any starting position.
One thing that you should check is that the bearing cartridge has not turned in the pedal body. There should be no gap between the shoulder of the cartridge (the aluminum ring on the inboard end of the pedal body) and the pedal body itself. If you do observe a gap, contact Garmin Customer Service in your region.