If your light is blinking on it then it should be grounded and tecnially working now, altho there may be a problem with the actual tape/wire.
You said you had to use some extra wire ...so does this mean you just tied the two together? if so depending on how you did this it can effect the rest of the fence working as the knot is breaking the current, however i cant give you a correct way of tieing it as it would vary every time, lol so you would just have to figure it out with trial and error :roll: .
if that is not the case then look at each end of your fence, how are they attached to whatever is holding the wire up. It should be to plastic , either handles, or other litte plastic hook thingys so it doesnt get earthed out. Even if you just tied it to wood , the wood will earth it out aswell, so it needs to be plastic.
And if you want a little tester...mack shift one i mean. get a bit of plastic , tie a small peice of wire to it, then you hold the plastic and put the wire on the fence, if it clicks then the fence is going, if not ...well then you have a problem still.
aslso schek a few different spots along the fence, not just one spot once.