mr-s500

Hi I have a 2004 s430 and I'm trying to install this dension module I have it connected at the back cd changer and it comes on and plays the problem is when I apply the break the cd changer and DVD nav changer in the back cut off and cut on which causes the module to stop and begin playing again idk how to fix this the voltage remains the same to the module when break is applied and when I take the module out the loop and connect everything back like factory the cd changer plays fine no cutting off when break is applied PLEASE HELP !!!!!!