You can find a vacuum diagram for a 1991 Ford Bronco 351 Windsor in a Chilton repair manual if the Haynes manual does not have it. You can also check with local auto stores.
When there is a problem in a vehicle, a diagram can help pinpoint some of the problems. A 1986 Windsor Bronco has a timing chain diagram in its maintenance manual.
Haynes manual
go to your closest auto parts store and buy a haynes manual for your model and year bronco , wiring schematic is in rear of book
Either in the back of a Haynes or Chilton manual or, best of all, in the authorized Ford wiring diagram from Helm. I have found them on Ebay and swap meets.
i would recomend picking up a Haynes or Chiltons repair manual Haynes is designed for people with little to know experience and chiltons is closer to a dealer ship shop manual
In a Haynes manual.
get a Hayne s repair manual they have the best diagrams
FROM A HAYNES MANUAL
HAYNES MANUAL OR CHILTON'S MANUAL
in the manual or haynes repair manual
Haynes manual or ford workshop manual
Haynes manual.