Hi , having trouble with rear wiper and high level brake light , trying to check if I have power going to tailgate , can't seem to find the fuse ,, or is there a relay I should be checking ?

The chances are your two faults are unrelated unless you have a bad earth connection.
Open the upper tailgate and have a look at the two earth points, they are on the tailgate hinges, should be in clean rust free condition. For the wiper check Fuse 10 20A on the rear fuse board in the drivers side compartment in the boot, the fuses are numbered from L to R looking at them.
The high level brake light has possibly just failed due to corrosion caused by water ingress, not uncommon I believe.
No relays anywhere.

Thanks very much , sorted those two out ,, next all cigaret sockets stopped working , checked fuse in boot and that's ok , any ideas ??

I had a similar problem when I "accidentally" shorted out the connections in the rear 12v supply. Checked every fuse, all were fine, but still no power.

Left it overnight and lo and behold, it worked again!

I guess the fuse fairy must have paid a visit.....  Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

How many fuses are there for the cigaret lighters ? As I can only find the one in the boot

There is a cig lighter fuse in the front as well, can't remember which one exactly but better check  MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

Fuses 1 and 7 on the rear fuse board both 20A depending how your car is wired.... there's two options.
No fuses on front fuse board.

May be I should have also said she is a 2003 TD6 ,,

The above applies to your car.
The cigarette sockets and accessory sockets seem to vary as to how they function.
Some are ignition controlled some aren't.