NS wing mirror not defrosting as it should! It appears different from the OS mirror in that the mirror glass does not have a black plastic surround around the mirror glass. My guess it has been replaced at some point possibly due to impact? Can anyone confirm what the standard mirrors look like?
Thanks in advance. Joe

 

Here is a picture of offending mirror (without plastic surround)

 

remove the glass, check if it has the heating element on the back and that it is connected.