New to my ram sport 50

Hello all. I just bought a 1985 dodge ram 50 sport. It is a long bed, and as plain jane as it gets
. I do have a couple of other dodges though. a 1971 d100 318/3 speed, a 1972 dodge motorhome, and my BABY, a 1963 d100, 413, 60 over (426 standard bore which is 425 i was told), flat top pistons, wedge heads, mild cam, lightened crank, 727 auto, and 4:56 gears.
Anyways, I bought the 85 as a daily driver, but am having some issues. Reverse lights coming on as soon as the key is turned on, and a loud audible tapping while running.
I only have 2 questions...where can I gat a wiring diagram for my truck, and is the vavle lash adjustable, and what is the procedure?
all help is welcome. thank you in advance

Anyways, I bought the 85 as a daily driver, but am having some issues. Reverse lights coming on as soon as the key is turned on, and a loud audible tapping while running.
I only have 2 questions...where can I gat a wiring diagram for my truck, and is the vavle lash adjustable, and what is the procedure?
all help is welcome. thank you in advance