Husqvarna TE 250 Workshop Manual page 401

Connect the diagnostic plug which was previously removed from the original
system.
Connect the 800094145 horn cable to the horn.
Connect the 800094145 horn cable to the racing system.
Connect the 800094145 horn cable pushbutton to the handle bar.
Part. N. 8000 B0148 (02-2008)
"KIT" ASSEMBLING INSTRUCTIONS
O.59
CONNECTING THE DIAGNOSTIC CONNECTOR PLUG
CONNECTING THE HORN PUSHBUTTON