noise on both screens in headrests

hello all. i have installed headrest monitors and ever since i installed them, there has been noise or interference. there is lines running across the screen and it jumps and flickers. all this only when the truck is running. they are clarion monitors being run off a jvc in dash double din player. from the player they go to a ferenheit video booster, then to the cables supplied by clarion.

i guess all that does not matter because i tried hooking up the kids portable dvd player to the video amplifier and it works good that way. there are a little bit of lines then but nothing like when the signal comes from the head unit. basically i have narrowed it down to a bad signal coming out of the head unit then getting amplified by the amplifier then being sent to the screens.

is there something that i should be doing different in hooking up the headunit? the display on the head unit is always perfect. i have it hooked up through an adapter harness into the factory wiring. should i be grounding seperately or.......??

thanks all

clarence

hello again guy and gals. well, i played with the system some more today. i cut the ground wire from the adapter harness and grounded it directly to the same spot as all my screens and everything else that i have installed which is on a factory ground bolt. that did not help at all. next i am going to try a seperate 12 volt battery outside the truck and then start the truck and see where that goes. is it possible that the interference / noise is coming from the unit itself inside? it is a model   jvc  KW-AVX800 double din in dash dvd player. just hopeing that someone has more ideas for me to try as this is getting extremely frusturating!!!

thanks

clarence

you've done all the right things to pin point your problem.  the only thing you dint mention doing was running a new video cable from the H/U to the video amp.  this would factor out the chance that it's a bad cable(and thus a bad H/U signal), if you decide to do this make sure you dont actualy run the wire under carpet just lay it across the seats(to avoid RR of an old clable for no reason).  can try something like this to: http://www.hifisoundconnection.com/Shop/Control/Product/fp/vpid/2680905/vpcsid/0/SFV/30046/sret/1. 

yeah i ran a cable over the carpet to. thanks for the idea though. i ran one from the head unit to the one screen; a little better but that was eliminating the amplifier. i could still see the lines but i can not run 2 screens without the amp so it has to stay. then i tried running another cable after the amp to the 2 screens and no change. still lines. so this is how i ended up where i am. thinking it is the head unit. or something before it. i talked to another guy who suggested i try grounding my video cable by soldering a wire to the ground prong of the rca then grounding that. i am also going to try a ferrule ( i think that is what it is ). it is what you see on usb cables to eliminate interference. i will try that on the video cable.

at this point i am looking for anything to try. as you can tell

clarence