My newly aquired GS has a bit of a wiring problem no doubt caused by a friendly rodent. The main issue is the rear lights etc. Having removed the LHS/F guard I see that the loom to the rear of the car diapears into the A pillar. I am having trouble getting continuity between the front and the rear. There must be another junction as the wires at the rear are a different color, but where is it,and what is the route of the loom.Please help.