GTI SINGLE WIPER CONVERSION

[KEVSGTI]

I bought a second hand single wiper conversion off ebay three weeks ago. Just got round to fitting it today and it wont work. I fitted it as the instructions said and when i put the wipers on the linkage moves a little bit then stops. (Its jamming and the motor keeps trying to move) The guy i bought it off had it fitted to a mk4 6n but he assured me it would fit my gti no probs. Its a RAIN X single wiper conversion.

Anyone got one of these and had trouble fitting it or can you help me out ?

Thanks guys