Rear Window Defogger Relay

[sqlpython]

In the fuse box of my 93 318i Sedan is an Orange 20 Amp Relay designated for the Rear Window Defogger.
  My rear Window Defogger does not appear to be working properly or at all.
I replaced the In Dash Climate Heater/AC Control Module but still no luck.
Checked the connections at the Rear Window all seems OK.
Checked the Defroster/Defogger Tracings on the Rear Window No Breaks all fine.
 Replaced the Rear Window Defogger Fuse..just because...
 Now I am about to replace the Rear Window Defogger  Relay mentioned in opening.

 Here is the Problem... bought it from Bavarian Auto on line..and it does not match my part number exactly as it is a 30 AMP...  I was told..
"Its Orange, they are all the same"..
Question??
  "Will or could this 30 Amp Relay cause issues?"  I am not comfortable with plugging it in...
   Currently looking to get a 20 Amp..

[sqlpython]

Follow up.........
 I had the BMW Dealer order the part..
The part has been superceded by a Green Colored Relay with a 5th center prong... Go Figure..
 Either way the Rear Window Defroster (Heated Glass) is still non functional.

 I have Replaced all Fuses (2) and the Relay in the Fuse Box( Power Distrubution Box) under the Hood/Bonnet.
 Also I have replaced the Heater/AC Contol Unit in Center Console.
 Further I have checked connection junctions at Rear Window and Traced the Wires in the Rear Window Glass for Breaks/Continuity..

 Next through the BMW Bentley Manual I have discovered that there is an additional wiring relay behind the Glove Box..
 When I remove the Glove Box to replace the Cabin Fresh Air Filter I will check that relay.
 Maybe I will be Lucky!