I have an aftermarket Headlight casing ( http://www.ebay.com/itm/FORD-04-08-F...dV50Eu&vxp=mtr ) this one to be exact. It takes 2 H1 bulbs which I put HIDs in but I am having a little bit of a problem with the high beams as the high and low should be on at the same time it works when I pull the switch towards me but not when I push it away. I think I need a better relay in between for the low and hi beams to keep a constant power to the low beams. Any thoughts? this is a 2006 f150

 

My thoughts, get rid of the HIDs. Those are halogen housings designed for halogens. You get glare when attempting to put HIDs in them, and those cheap housings are going to melt from the UV radiation of the HIDs.
Now to your question. You will need to make or run a new relay harness fit the high beams. Our trucks don't keep the highs on when the lows are on and either do these headlights. . the reason being keeping the lows on with the highs will give you way to much forgetting hindering your distance vision.
The Retrofit source has a relay harness that keeps the lows and highs on at the same time, but I don't think it'll work on your application.