Dual tank wrg

Buy a factory service manuial. Go Beg a dealer if they still have the books to copy the page for you. Find someone with a mitchell 1986 wiring book for GM trucks and beg them to copy the page for you. Charles

This might do ya

sorry let me try this again.

Hey Demon,

Friend of mine and I both had 80 models, his was gas mine was diesel. His dual tank switch quit working, he bought a new switch, that didn't fix it.....bought a new transfer valve , didn't fix either.....several days before all this he remembered his dome light quit working.....checked and it blew the fuse.....replaced fuse to dome light....guess what.....dome light and transfer switch worked also!!!!! He bought the new switch and the transfer valve for no reason, all he should have done was check the fuse box! The diagram and fuse instructions didn't even show the transfer switch being on the same circuit as the dome light! just for your info as your 86 is probably using the same or similar diagram.......Mark