Originally Posted by
Sasha1972 
One important thing where I would disagree with some of the previous posters - I would stay away from anything that involves monitoring his sobriety. You've mentioned breathalyzers and his own self-report, both of which are causing problems (he lies about self-report and he complains, interferes and obstructs with mandatory breathalyzers). Someone told me once "it's not your job to catch him drinking, it's his job to prove to you that he can be trusted to stay sober".
I think breathalyzing is a bad idea when you're still living with the alcoholic, but it's a little bit different when you're separated and he is taking the child for visitation. In those circumstances, it isn't so much about monitoring his drinking as it is protecting the child--like making sure the child is properly bucked into the car seat.
But it's true that if that isn't working for you because of his attitude and the accompanying uncertainty/stress on you, then it might not be the best solution.
Have you checked into SoberLink? That would take you out of the loop altogether, in terms of making sure he complies. I don't know what it costs, but it's worked very well for some people here. And the cost should be borne by him, not you. His drinking is what has made it necessary.