I am going to comprise this from multiple how to's that i have found, due to the fact that one single how to only showed some steps. Some for the 02- and some for the 02+ focus.
This How to will work for the 02+ Focus "Hatchback" when installing a set of Euro tail lamps into the veh.
Any info i will provide is for the user at their own use, i am not responsible if you mess something up or burn out a module due to faulty wiring or hooking it up without the use of some type of multimeter to test your wiring.
And here we go.
1. Lower your glove box by pushing in on the tabs and lowering it it down, behind the glove box you will see your GEM module, it will have 5 plugs with yellow square holding tabs on them.
2. The 3 Plugs you are going to need are the Blue, Green and Gray Plugs, the plugs are color coded under the yellow locking tabs, you may need a light to notice which is which.
3. In the Gray Plug find the Blue wire and cut it in half about 1 inch below the connector incase you ever need to reconnect it again.
4. In the Green Plug find the Blue/Red wire and cut it the same way as in step 3.
5. Now in the Blue Plug, find the Blue/White wire strip some of the insulation back and attach the blue wire you cut in step 3 into that wire. Attach the blue wire going away from the plugs that you cut "not the one going into the Plug".
6. Also in the blue plug find the Blue/Red wire, and strip back some of the insulation and attach the Blue/Red wire you cut in step 4 into that wire. Once again attach the wiring going away from the plug, not the one going back in.
Here is a Diagram from one of the How To's
Thanks to The guy who posted it, im not sure who it is cause there was no user name....sorry.
Be sure to soder your connections if you didnt use t-taps and tape up any exposed wiring.
~Now the front part is complete, this will give you your independent Parking light/Stops and Turns for the separate bulbs in the rear. So put all your crap back in your glove box and close it back up.~
The next section is done at the rear of the Veh, this part i got from a member of FF and it worked perfect, so i am going to basically Copy and paste his instructions.
If you only do these instructions without the above posted steps in your 02+ Hatch with the GEM, when you step on the brakes you will have your brake and blinkers come on at the same time.
So Many Many thanks to Darth Focus
on this part his step by step was very helpful.
1) Remove panels, carpet, sub box, etc. to make access to the drivers side quarter panel (in the trunk). You will see two plugs, a gray and blue.
2) In the blue plug is a green/ black wire - cut it after the plug. Thats for reverse and you wont need it for the tails (you will need it when you add a lower mount reverse light later).
3) Remove tail lights.
4) At the gray plug, find the green/ yellow wire, splice in and add TWO long sections of wire. Run each wire to the tail lights. I make a small hole in the rubber grommet with the tail light harness (under the tail light that is now removed). Run your wire out to each light.
5) On the tail light plug, cut the blue wire. Make sure you leave as much room as possible to splice the blue wire later.
6) The wire you ran to the tail lights goes to the SOCKET SIDE of the blue wire. You now have parking lights/ brake. Do this for each side.
7) Now, at the two pin reverse plug, cut the green/ black wire and use some spare wire to exten a wire between the green black wire from the socket to the blue wire you cut in step (5).
As stated previously if you do it all in these step your euro tails will work perfect and not have any issues with blinker/tails/brakes etc.
Once Again thanks to everyone for their helpful info....I just hope this helps people out now so they dont have to goto 2+ different how to's to get the euros to work.