MERCEDES BENZ E320 AIR CONDITIONER

My A/c Have Been Charged The Diplay Light Wont Come On And The Ec Light Want Go Off. Their Is No Leak In The A/c System. How Do I Get It To...

I Have Charged My A/c System And It Dont Leak But The Display Light Wont Come On And The Ec Light Want Go Off. Will Some One Please Answer...