Problems with Y-harness with TH9x

MuffinPilot

Junior Member
So I just got my TH9X going and attempted to connect my aileron servos via y-harness. Not only do they not move in the opposite direction, they don't move at all. Tried all the " no duh" trouble-shooting. I got it to work with ch1 & ch6 connections, thus negating the y-harness, thus negating my goal. Any suggestions from R/C land?
 

Epitaph

Ebil Filleh Pega-Bat ^.^
Mentor
I'm not sure it's so much a program problen as much as a problem with the y-harness... try plugging just one servo directly into channel 1, and that should work... if it doesn't, then the 9x has some freakie programming I'm not aware of and I can't help you much... but it should work. If so, get out your multimeter and check the continuity of the 3 cables from the male to the 2 females in question, as it might just be a break in one of the connectors that can be solved with a little soldering. If you don't have a multimeter, put the harness on channel 3 and plug your ESC into one of the females... if the receiver turns on but there is no throttle control, then it,s the PPM cable. If the receiver doesn't even turn on, then it's one of the other 2... in this case, disconnct the red power connector fron the ESC male and connect an external battery to the receiver. If you have throttle control again, then the fault is the red cable, and if it still doesn't work, then it's the black (or brown in the case of the yellow-red-brown leads) negative that's giving the problem.

Another thing to point out in case you have no experience with y-harnesess, you say about opposite direction and all that... if you are using it directly on the plane, then the ailerons will move in opposite directions. But if you are testing it all on a bench with a couple of loose servos, the servos should move in the SAME direction. What changes the direction is that the servos when ibstalled are done so in opposite directions, giving the illusion that one reverses, but really they both turn in the same direction. All a y-lead does is join all the PPM's togeather, all the positives togeather and all the negatives togeather with no electronic components involved... you may already know all this, but on the offchance you don't, just thought you should know as to know what to expect when you get it working.

Good luck!
 
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xuzme720

Dedicated foam bender
Mentor
Epitaph has nailed it for you. If the servos are not working when the "Y" is plugged into a working channel, there is something wrong with the Y-cable. Or your servos are plugged into the y wrong...make sure the lightest color wires all line up and plug into the Rx where the signal goes.
Signal wires will be either white or yellow depending on color scheme. Brown and black will also line up together as grounds.
 

MuffinPilot

Junior Member
Continuity on the y-harness is good. Even tried the motor connection, sucker fires right up. Leads all align to proper color. I'm convinced its the transmitter programming. But no trouble-shooting guide in manual (not sure who wrote the manual, but it's very poor English, and it actually has the word "wanton" in it). But thanks for the help. If I figure it out, I'll let ya know what I find.
 

Epitaph

Ebil Filleh Pega-Bat ^.^
Mentor
If you plug just one servo directly into channel 1 and no other servos anywhere else then it's not the radio. A Y-harness is nothing more than 2 servo cable extenders joined togeather into one male plug.

I had a problem with my servos on my bug because both had the connections slightly enlarged from use, and were giving a false connection.

Try putting it into channel 2 and moving the servos with your elevator control... There's no fancy mixing or programming there!