Hard starting cold 99 jetta

My 99 Jetta is very hard to start when cold. I checked the glow plugs today according to my book and also checked the harness.They both checked out. I am trying to figure out which relay is the glow plug relay under the dash and how do you check it or do you just replace it.Thanks in advance for any help.

Go back to the main A3/B4 forum and search in the GP relay thread..., it is ALL there!
Behind the fuse box nestled under the dash AND you need a good flashlight to seen the thing.