I've got a 99 4.6 expedition, and the ac blows cold but than starts blowing warm. If i turn it off and than back on it blows cold again. I've noticed it cuts out if I take off a little quicker than normal from a light or have to brake a little quicker than normal. I took a quick look and could not find any vacuum leaks. I've also replaced the a/c / heat control only to have the same results. A co-worker with the same specs is having the same issue, is this a common problem?? Any help is greatly appreciated. Thanks