Help before I take out a mortgage for this key from merc at £180. I need a remote infrared key fob for a C180 - 1996 - part no. 21076000/306. I got 1 from ebay but despite new batteries had no power when pointing it at door and I also had the key tested. I was told that the key(s) have to be programmed but if there is no power in the key then there is no point. Please anybody .. help. I cant keep climbing in and out of the passenger door lol