The thing is that Field builder has its field, and in this case `“load”` event means that field builder is loaded, with the fields, but fields are not loaded by itself.

In case of Keyword field, it uses XSLT transformation to render field view.

Unfortunately Keyword select control does not fire any events which might help in this case. Thus I would suggest to extend `_onItemDraw` method from  `\WebUI\Editors\CME\Controls\KeywordSelect\KeywordSelectControl.js`

Eric gave a good reply on how it can be possibly done in a similar post:
http://tridion.stackexchange.com/a/1856/206

The extended code will look like:

    (function ()
    {
    	var overridenKeywordSelectControl$_onItemDraw = Tridion.Controls.KeywordSelectControl.prototype._onItemDraw;
    	Tridion.Controls.KeywordSelectControl.prototype._onItemDraw = function KeywordSelectControl$_onItemDraw()
    	{
    		// Call original method
    		overridenKeywordSelectControl$_onItemDraw.apply(this);
    		
    
    		// Do an action you need
    		var element = this.properties.container;
    		console.log(element.innerHTML);
    
    		// Or fire event which you can handle elsewhere
    		this.fireEvent("extension_oncontroldrawn");
    	};
    })();