Load control template from 14 hive in SharePoint 2013

Hello. I've a problem with Solution migration to SP2013.

My solution instaled in сompatibility mode (hive 14). 
Solution creates a Custom Content Type.
Template locates in \14\TEMPLATE\CONTROLTEMPLATES\MyField.ascx

When I try to get Control from TemplateContainer, I've got Nothing.

If I copy temlate to "\15\TEMPLATE\CONTROLTEMPLATES\MyField.ascx" TemplateContainer.FindControl() works fine.

So, question is - how can I load template from 14 hive?