I have an '85 C-10. Wipers would not work on variable speeds and would not turn off unless I manually turned the wiper control on the steering column to the off position and held it there momentarily and the cruise control did not work. Mine has wipers/washer/Cruise control/turn signals. First...
Built one for my '85. Made it out of 1/2" Poplar shelving from Lowe's, stained it. Keep all kinds of "essentials" there and built it tall enough to hang a 4-point lug wrench on it.