1. 2008 Cadillac CTS With Original Antenna

2. 2008 Cadillac CTS With 09 Shark Fin Antenna

3. Parts Needed
P/N (09 STS Antenna Base)
P/N (09 CTS w/U2K option antenna Base)
P/N (09 CTS w/o U2K option antenna Base)
P/N (09 CTS Crystal Red Fin)
P/N (09 CTS White Diamond Fin)
P/N (09 CTS Black Cherry Fin)
Always verify the part numbers for your option and paint code

4. Rear Overhead Reading Lamp
To Remove The Lamp Assembly You Gently Pry It Down Around The Perimeter
3 R-174 Coax Cables Attached to 08 Antenna
Jack. There Is A Small Clip That Needs To Be Gently Pulled Down To Release The White ClipConnector
Remove This Wiring Connector From Jack

5. Removal Of Original Antenna
Alignment Pin (Not Used on Fin Antenna)
Remove this 9/16” Bolt and Orange Clip
3 Coax Cables That Will Be Disconnected At Rear Of Headliner

6. Sail panel
Carefully pry out Air Bag
Access cover
Then remove 5/16” screw
This helps drop the back
End of the headliner

7. Carefully Pry Out Air Bag Access Cover To Reveal And Remove 8mm Screw

8. Gently pry cover from the top out
exposing 8mm screws to remove
the access handles
A jeweler’s screwdriver or a tool with a small hook on it is ideal to prevent damage to the cover

9. Gently pry cover from the top out
On both sides exposing 8mm screws to remove the access handles

10. Remove the trim ring around the sunroof opening
Gently pry the sides out then the back. This plastic ring
will come out
You will see how it goes together

11. There is a “rosebud” clip right here that attaches the headliner to the roof. Just pull down gently to bring rear headliner down. It goes back in very easily.
Pull down right in middle of rear headliner

12. Red boxes show location of three coax connections above headliner
XM Radio
GPS
Cell Phone

13. These are the 3 colors of plugs you will have to disconnect
“C” Key
GPS
“D” Key
OnStar Cell
Phone
“E” Key
XM Radio

14. This is the type of connector (jack) that you will find above the headliner. There will be three: purple, blue and leaf green.
Push here to Release plug

15. 08 CTS 08
09 CTS 09
Note* By using the 09 STS antenna all you do is ensure the fakra connectors are the same color as originally
This is an ‘08 CTS with the three leads.
You must transfer these connector
Ends to the 09. The colors of the
Wires match. Just remove the
connector ends and swap end per end
Ensuring the wiring colors match

16. Locking Tab
Fakra Removal - Tab Type 1. Carefully pry out the locking tab using a jewelers screwdriver Carefully pull cable out towards the rear of the connector.  
Fakra Removal - Tab Type
1. Carefully pry out the colored locking tab using a jewelers
Screwdriver (really only requires one “click”).
2. Lift up “c” shaped tab on adjacent side of connector
3. Carefully pull cable out towards the rear of the connector.

17. ‘09 STS Antenna Base
To remove coax cable use a jeweler’s screwdriver to pry up the pink clip on the side of the connector. It only has to go up one click

18. Step 2. Insert a small pick or
something and pry up, this will
release the coax connector

19. Remove Original Antenna on Roof
This hole is not used for the fin and will have to be filled in with silicone or etc.
After 9/16” Bolt and Orange Clip is Removed From Underneath Pull Antenna From Top of Roof

20. Need To Make Round Hole Square
You will have to make the original 1” round hole into a 1” square hole. I used a 1” file to do this. Make sure the square is parallel to the rear of the roof
I suggest the edges of this square be covered with primer, touch-up paint, etc. as desired

21. Install Replacement Antenna
Alignment Pin (Not Used on Fin Antenna)
Tighten this 9/16” Bolt and Mounting Clip. Note: 09 Clip is slightly different but works the same
3 Coax Cables That Will Be Re-connected At Rear Of Headliner

22. ’09 STS Antenna Base (Top)
OnStar Cell Phone
GPS XM
Shows ‘09 STS Base With The Three Connectors Configured For 08 CTS

23. OnStar Cell Phone
GPS
Top View Of Base With Orange Cover Removed
XM Radio

24. Shark Fin Mounted on Roof With Protective Cover Still On
Orange Protective Cover. This Will Be Removed Before the Fin Is Snapped On

25. Bottom of 09 STS Antenna Base

26. Bottom of White Diamond Color Shark Fin Cover

27. White Diamond Shark Fin Cover

28. ’09 CTS Fin Antenna Attachment Points
This The Final Step. Snap On The Fin Using The Attachment Points