Hi there, problem sorted many thanks
Upto here I've seen where I was wrong and understand. Although I dont understand how you managed to get those values for i1 and i2?... the long line in the voltage source symbols represents the positive end, and you assume a current of i1 in the left-hand loop, and a current of i2 in the right hand loop, both flowing clockwise, I get i1=5.3167 amps and i2 = 4.7778 amps. From this you can compute the output voltage of the circuit as 12.933 volts. So the Thevenin equivalent at terminals A and B is a 12.933 volt source in series with 1.499 ohms. This might even be correct if my assumption about the polarity of the voltage source symbols is right.