Ruddybloak is correct you cannot mix duel elevator servos on the 6EXA. The easiest way to link the 2 is to get a Y harness but make sure you get a reversing Y harness. I am guessing you didnt anticipate the mixing not working so when you look at your levator servos they are probably both facing the same direction. Normally when you mix these you reverse one's throw. You will see if you dont get a reverser that they will throw oposite. You can turn the oposing servo around however that would also require you to make a new control rod to length again. Sometimes its eaiser to get a reversing Y. I had the 6EXA and thats one of the reasons why I got rid of it.