hey guys i have installed a sony head deck in my xf and i will play fine but when i turn it up it is like isnt getting as much power the screen gets dull and the brite and the sound stops and starts. so if there is anyone out there that can help me hit me back thanx

That sounds highly unusual.

I would guess there is a problem with the deck, but To rule it out, run a dedicated power wire from the battery (fused of course) and test the deck using that power supply. You can use it for constant and ignition power for the test.

If it doesn't do it off that supply, then there is a problem with the wiring in the car!

are you using factory loom if so the head unit might pull too much power and need to have heavier main power wire

You never had any problems with power before in the car? Sounds like the headunit is just drawing too much current when it starts to pump. I had a similar problem in my Datsun 260Z with my JVC headunit. Fixed it by running a dedicated power lead from the battery to the headunit. 5mm housing wire with the trick a bit of overkill I guess