I have been using a Futaba R149DP receiver with JR retract servos(NES 703) on four of my planes with no problem. However, on my next plane a WM P51 GS, the two retract servos do not work with that receiver. I have spent hours looking trying different combinations to identify the problem:
-Two JR retract servo connected to the receiver with a Y harness does not work
-Two JR retract servo connected to a airtronics receiver with Y harness works
-One JR retract servo connected directly to the Futaba receiver does not work
-One 3001 Futaba servo connected to the receiver works
-Use of servo test on my Futaba C9 radio works the servo with some jerky movement
-Connect channel 5 on the receiver to the flaps with Y harness works

I am using 6V batteries, could that cause the problem. Does the JR retract servos(NES 703) work on 6V batteries.