Glow plug relay Where is it e220 2003

[Bombx3]

Hi
e220cdi 2003
My glow plug light was on and the Star came up glow plug fault

2 glow plugs busted so i replaced all 4

Warning light went out but next day it has come back on ,when i turn on the ignition it does not go out
Could the new plugs failed
Could it be the relay? where is this thing?
The car runs ok i just dont like having a light on

Cheers Ray

 

[a111r]

It's on the near side, behind the washer bottle and in front of suspension turret.