Gentlemen. Here is a strange problem that I experienced. I have old (AM) Futaba (4) Channel equipment. I needed a (5) servo configuration for a GP Dazzler that I was building so naturally fitted a Y Cable for the ailerons. I noticed that when (ground) testing the aileron drive, one of the servos did not have any torque, ie, you servo would move but could be re-positioned with slight finger pressure (yikes!). When I used the Y cable as an extension on a (4) servo setup, the servo, at times would not actuate to drive the aileron-horn, setup. The other Y cable that I possess did exactly the same thing. Both Y cables were purchased new. Both Y cables were plugged directly into the receiver. The plot thickens - by putting a heavy guage cable between the receiver and the beginning of the Y Cable, a cure was provided for both instances. Anyway, just grist for the mill - hope it helps someone.

Strange.
Almost sounds like there was a problem with the connector on the "Y" when you plugged it into the Rx. Maybe a corroded pin or something. Then, when you removed it and put a new connector on the Rx, it wiped some of it away.
Did you try just the "Y" again?
Dennis-

DBCherry - tried the Y cables on another AM Receiver with exactly the same result. I've given up trying to figure it out, however the problem could have led to un-explained crashes, eh? The USER would possibly build the same way again and at odd moments the problem would develop with disastrous (and unexplained) results. The weird thing was that using either Y simply as an extension (the other Y leg left unloaded) resulted (on occasion) no aileron actuation. I did not try the Y on any other function than ailerons - maybe try that later, eh? As I said - could have been a bear to determine the cause of a crash.

I have had the same thing happen with my Futaba FM RX. The only dif was my problem was after the Y. I had to add an extension to make it to the end of my 75!QUOT! wing. I too used a larger wire and the problem was fixed. I think the problem was too much voltage loss in the wire. I thought about using a 6v battery (5 cell) to see if that fixed the problem but I have not gotten around to it.

i dont know your experience level so im assuming youre a beginner. if you have the money get a 6 channel computer radio ( futaba 6exa is 200). it has 6 model memory so you dont have to buy a new radio for every plane, just a flight pack. it will also couple channels 1 and 5 using the receiver (it might be 1 and 6 im not sure) for dual aileron servos, and if you want them, flaperons (ailerons that also function as flaps). it might just be a faulty y connector