initially you would have to wire it to the handbrake earth so that when the handbrake is lifted...then only then can u watch dvd's....otherwise when it is down and in drive mode...you cannot see picture but can still hear sound for those that store music mp3's onto a dvd format disc.
However, should you wnat to see dvd picture whilst on the move then all you need to do is to wire it to a constant earth...to save you time and hasstle...cut the wire short...it may be lime green colour perhaps...but neway..cut it short and just patch it into the black earth wire on the stereo wiring loom...n there you have it!
as for your front speakers...get a multimeter to the speaker block and check to see there is no break in the cable sumwhere....do this by means of setting the multimeter to "continuity" which is the little speaker type symbol...u'l know when it is set as if you touch the 2 probes together..it will either bleep or show a moving set of "0's" on the screen. if you get nuthing from the centre 4 set of wires on the block..then there is most definately a break in the cable sumwhere...otherwise if you do get a reading..then your speakers are probably shot.
See if you can get a picture up of your state of wiring, then a may b able to be more specific about where to chek for faults
