ECM differences 32534-05A and C

[Low1200hd]

Does anyone know what the difference is between the 32534-05A ecm (happens to be on an 06 Dyna) and a newer 32534-05C ecm. Mainly looking to see if the Pin 3 (tach output, pink wire) is actually useable on the -05A? My wiring diagram for an 06 35th Anniversary shows no labeling for pin 3 on the ecm. But the -05C for a touring bike shows the Tach out is connected to the tach.

I am installing cruise control on my 06 Dyna 35th Ann. The cruise control unit is a 70955-04 from an 06 RK. I have, repeatedly, watched the video by Frogaliscious ( Cruise Control install on 2012 Dyna Switchback FLD. And using the schematic they created and using factory wiring diagrams. I kinda modified what they did by using the Tach signal from my 06's ecm. If it is actually there and operative. Everything I can find on the 32534-05? (A or C) seems to suggest that the signal is on pin 3 just not used on my 35th Dyna.

Jack B.
'06 Dyna 35th Anniversary

[Hilly13]

I don't know if this is of any help but on my 06 wideglide I replaced the standard speedometer with one from the Harley catalogue of the time that had a tacho and speedo in one unit, it was plug and play, so one of the wires you have at your speedometer plug is definitely for the tacho.