i logged into my sip acc and there are no wiring diagrams for the 1986 flht. would have included it in my library. if my manual in not correct, this info would be invaluable.
unfortunately, i do not facebook, tweet nor twitter, matter of fact, everything i do on the net is hidden, or at least to my ability to leave no foot prints in the sand. right now, i am pinging out of britan and next time maybe bangladesh.

 

I am using an official HD manual, part #99483-90 and it has complete wiring diagrams fo 1986, 1987 FLHT/C fairing including the gauges. I took those sheets to Staples office supplies and they scanned them, then printed them out on 24x36 sheets, size of blue prints. Very legible.

 

yep, that was the way it was way back, my 1974 ch is like that and i really do not see much diff as far as cagers go, i live in the #5 of the worst states and the only thing that would gab their attention would be surface to surface missiles.
i would use a time delay relay myself. i tried a relay using the oil pressure sw and it worked till i up to halogen lights. the old incandescent bulb would take the rapid current rush but the halogen will fail. so it is back to the sw.
i will search some more, wrong info is worst than no info. usually i will just reverse engineer if needed but no bird in hand. glad you got it sorted out.