Where can you find a wiring diagram for 1979 international 384 diesel tractor?

I bought a manual at stevens tractor company. Its in coushatta Louisiana. My manual has the wiring diagram in it. Their number is 1-800-333-9143, and their address is stevens tractor company 3715 hwy. 71 coushatta la. 71019. Their fax number is (318)-932-9800.