I'm running Autocad 2011 another trade has upgraded to Autocad MEP 2013. I can't seem to figure out wich object enabler to download so I can see his light fixtures and equipment in my drawing, been at it for 2.5 hrs with no luck I'm raising the white flag, any help would be greatly appreciated.
Interoperability between later-version verticals and ealier-versions of either vanilla or a vertical, is non-existent. Although there is no _technical_ reason for not providing an OE for 2013 AEC content that could be used by 2011, it's not going to happen.
Your two options are either to upgrade your installation to 2013, and stay in synch with the other trade(s), or request that they ExportToAutoCAD before sending you files.
Third choice would be to install TrueView 2013, and use that to convert back down to 2011 -- I'm not 100% sure that will export the AEC content to something you could use or not.