Mercedes Benz repair: A/C Relay, mercedes benz 300se, number search results

Question
Air conditioner works sometime.  I believe it is the A/C Relay but cannot locate to replace.  Where is the A/C relay located on a 1988 300 SE.

Answer
Answer:
Mercedes-Benz A/C Control Diagnostics
Steve Brotherton, ImportCar?‡, June 2000
http://www.mercedesshop.com/Wikka/AcDiags

Climate Control:
http://www.mercedesshop.com/shopforum/showthread.php?t=142408

A/C Relay picture
http://catalog.eautopartscatalog.com/mercedesshop/sophio/image.jsp?title=A/C%20R...

PART NUMBER SEARCH RESULTS WITH PRICES
Vehicle 1988 Mercedes Benz 300SE
Part: A/C Relay
R1140-12156 A/C Relay Germany IN STOCK $132.12  
 
R1140-70276 A/C Relay Programa IN STOCK $102.17  
  
http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=merc...