I have the shop manuals for my 1996 S10. two blue manuals about the size
of small phone books

I am trying to help a friend with a problem on a 1996 1 ton tow truck.
It blows the tail light fuse when the high beams are put on.
Seems to be the multi function switch.

I went to may manuals to look for the wiring, but my two shop manuals
don't seem to have these wiring diagrams in them.

Where can i find the wiring diagrams?
What manuals are they in?

Bob