mondeo mk4 a/c and headlight issue

hello,ive got a problem with the a/c on my mondeo titanium x sport.

after reading through this fine forum i found that the purple wire from the pcm was indeed broken so that was repaired but still no a/c (sorry meant to say i had it regassed first and the a/c wouldnt work).

So the next item we found was that the rad fan was also u/s so that has been replaced but here is where things get a bit strange!

If my mechanic plugs his diagnotic machine in and does a reset the a/c works for a minute and then stops again!!so i am wondering whether i have to book it in to my dealers for a proper ford diagnostic test or if one of you fine people could could point me in the right direction?

Now my second issue is that there is a fault with my headlamp control unit so that was replaced but i still have the warning message on my dash!again does this need a ford diagnostic reset?or is there another way?i am loathed to pay fords going rate but at the minute i dont really see an alternative.