Same here TrackIR 5, 5.4.2 drivers + x64 KSP = nothing doing, no light on. Can't test the 32-bit as I have too many mods.
Here's a workaround, 'til Squad get around to putting the correct TrackIRUnity.dll in the x64 folder, though:
Replace the TrackIRUnity.dll in the "Kerbal Space Program\KSP_x64_Data\Managed" folder with the one from KerbTrack 1.2 http://kerbal.curseforge.com/ksp-mods/224254-kerbtrack (it's in the "GameData\KerbTrack\Plugins\" folder).
or
Replace the TrackIRUnity.dll in the "Kerbal Space Program\KSP_x64_Data\Managed" folder with the one from here: https://github.com/medsouz/Unity-TrackIR-Plugin-DLL/releases
Start the x64 version and it's green lights and twisty-turny views all round!
Both options work, see which you feel comfy with (downloading the zip from KerbTrack won't make Chrome & antivirus things get scared about downloading a .dll)
(reports of bad spinny-spinny in map was thanks to me trying to map view to my rudder pedals by mistake in a vague attempt to get TrackIR working, then forgetting I'd done it because it didn't work. Very Kerbal.)
-dead-'s post in [1.1] Track IR not detected in x64 was marked as the answer