I have 86 chevy half ton pickup needing a harness. will a harness from an 84 half ton work for me as I have one availible to me
Only if it has the same engine/trans combo. I don't remember any major changes happening between 84 and 86, but taking that into account, thoroughly label everything you're removing, and bring the digital camera along to snap pics of the harness with the labels on them as you remove each connector. Better safe than confused as all heck!