connecting gps, radar audio to headphones

Ok I dont know what I am talking about. Thenm explane to me why you are using that cable when there are no RCA's in either one of your units nor your headphones?

Half ass response? Im not on here to argue with you. You came on here for some help and I am trying to help you. And obviously I am the only one thats been trying to help you. If you dont want my help, then simply tell me and I will gladly move on. I do have other ideas on how you can do this one so dont get nasty with me if something doesnt look up to par for you. What do you think of this diagram? With this diagram, you will be able to use the one you pictured, but youll also need more cables and connectors. But this one will work:

Look, Im not interested in arguing with you...we are back at square one. 

Again, the last diagram you've drawn is exactly what I have now.

A stereo 3.5mm jack cable does not have two wires.

A mono  3.5mm jack cable does not have one wire.

Will diode isolating each mono channel solve my issue with feedback?

a stereo 3.5 cord does have 2 wires. Though when you look at it on the outside, its 1 cord, but cut it open  its 2 wires. One right one left.

A mono 3.5 cord does have 1 wire. Its mono meaning 1.

As far as I know, you should not have any feedback. If the setup you have now is the same as my last diagram, you are never crossing the right and left channels therefore you shouldnt be having any feedback UNLESS one of the cords is defective and the sound is jumping from right to left.  A diode would only prevent feedback from going from one unit to the other. It wont prevent them from bleeding together into my headphone speaker. Another thing you could try is simply dont get any stereo cords between the gps and the rca y connector. If your gps is set up to put out the exact same "sound" for both the right and left, then if you use a mono 3.5 plug instead of stereo, it would be the same thing. Give that a try. If you are still having the same problem, then I dont have any other ideas. Sorry.

Audioman...there are two wires in a mono cable, one positive and one negative..if there was only one there would be no sound..OK? 

That's why I  assumed you dont know what your talking about..you cant even comprehend the very basic prinicpal of how sound is generated through the use of electricity.

Finally..found the answer.

http://cyclegadgets.com/Products/product.asp?Item=KT-ROR