I went ahead and installed the block heater and battery warmer on my '06 FEH. Everything went smooth, except for the fact that the actual heater plug that goes in the block is not in all the way. It is tightened down until snug, but is still showing five threads. Is this normal? I know the plug you take out of the block is not that deep to begin with, but I want to make sure I do not have a problem with the heater plug. I have attached a picture of mine installed.

 

I think mine was like that as well but you might wanna recheck the threads and everything.

 

It's a pipe thread, therefore tapered, you will onlybe able to tighten so much. If its not leaking don't worry