Sorry I took a while to get back to this message, I was busy today. It seems that you already figured it out so just always make sure that the " |image = " code is input with the rest of the templates.
You need to actually upload the picture to the wiki. Then you need to click the insert image button and assign a size to the image (200px, 250px, etc). Also, you can't leave the word "thumb" in there otherwise the picture will come up as a thumbnail in the template.