guess i was wrong only one above the starter that i found in the manual. doesnt make sense to me.

From what I can tell, the location determines the "A" or "B". The Bonn 3800 i used to have also had two, with the B port close to the single sensor on the short star...just my 2 cents. Thanks, I will try to replace it tonight.

Fixed! Thanks. Guess it is just one for the shortstar

thanks for updating your fix