You have more than one fuse box. Fuse numbers location in box what they control and contents of each is in your owners manual.
A 1991 Toyota 4runner is bigger than a 1990 4runner
ignore pls
go to the Toyota store n ask them if they don't no go on Google and type in this how toinstall rear speakers on a 1991Toyota 4runner
it mounted on the throttle body
Fuse block in engine compartment right side.
The headlight circuit is protected by a self-resetting circuit breaker. Something in the circuit is drawing too much power and the breaker is cycling on and off.
By your left foot about 8 inchs up on driver side floor board
Freon but you can convert over to the new stuff
look on the intake manifold it will be stampes into the manifold cast.
The thermostat on a 1991 Toyota 4Runner is located on the engine block. It can be found by following the large hose coming from the radiator.
dexron atf is what Toyota recommends, ive used it a hundred times its fine
Shut it off. Either a switch or cut wire from battery