What fuse protects the 4 wheel drive indicator light circuit?

Fuse 10, a 20 amp fuse, feeds the 4 Wheel Drive Indicator Light circuit; the circuit is hot when the ignition switch is in Run or Accy.

What fuse powers the seat belt warning buzzer?

Fuse 4, a 7.5 amp fuse, powers the Seat Belt Warning Indicator Buzzer circuit; it is fed from the ignition switch and hot in Run.

Where is the oil pressure switch located?

It varies by engine: 300 cid — on engine, LH rearward, below valve cover; 351/400 cid — centerline of engine block, full rearward; 460 cid — on top of engine rearward of carburetor; 302 cid — on engine block, LH lower side, near oil filter.

At what pressure does the oil pressure switch open?

The oil pressure switch opens with oil pressure over 6 PSI, which turns off the Oil Pressure Warning Indicator Light.

Where is connector C420 located and what does it look like?

C420 is on the toe board near the dimmer switch; it is a rectangular, brown, 2-terminal connector used in the Seat Belt Buckle Switch circuit.

Home/ Registry/ Ford/ Bronco/ 1978-1979/ 1979 Ford Bronco/ Photo supermotors.net/registry/media/1032648

1979 Ford Bronco F100-F350 Wiring Diagram - Brake, Oil Pressure & Seat Belt Warning

Ford truck brake, oil pressure and seat belt warning wiring diagram with fuse 4

‹ ›

Warning-light wiring: dual brake warning switch, oil pressure switch (varies 300/351-400/450 CID locations), seat belt buzzer through fuse 4 (15A) and fuse (20A), with connector and ground table.

AI caption August 2014 · Photo 29 of 48

This page (29) from a Ford wiring diagram manual covering the Bronco and F100 through F350 trucks shows the warning indicator light circuits. Four circuits are traced: the Dual Brake Warning Light circuit (hot with ignition in Run/Start from Splice 401, red/yellow wire through connector C208 to the light, then pink/white through C306 to the Dual Brake Warning Switch on the brake control valve assembly); the Oil Pressure Warning Indicator Light circuit (through C208 and C220 on white/red wire to the Oil Pressure Switch, which opens with oil pressure over 6 PSI); the 4 Wheel Drive Indicator Light circuit (protected by Fuse 10, 20 amps, black/green wire through S403, C503, C416, and C417 to the Differential Lockout Indicator Light Switch); and the Seat Belt Warning circuit (Fuse 4, 7.5 amps, feeding the Seat Belt Warning Indicator Buzzer, Seat Belt Warning Indicator Light, and Seat Belt Buckle Switch via connectors C419 and C420, grounding at G701 via splice S805). A legend table lists component locations by engine (300, 302, 351/400, 460 cid oil pressure switch locations) and connector descriptions including terminal counts and colors for C208, C220, C306, and C420.

Is this accurate? Sign in to help verify it.

Frequently asked questions

What fuse protects the 4 wheel drive indicator light circuit?: Fuse 10, a 20 amp fuse, feeds the 4 Wheel Drive Indicator Light circuit; the circuit is hot when the ignition switch is in Run or Accy.
What fuse powers the seat belt warning buzzer?: Fuse 4, a 7.5 amp fuse, powers the Seat Belt Warning Indicator Buzzer circuit; it is fed from the ignition switch and hot in Run.
Where is the oil pressure switch located?: It varies by engine: 300 cid — on engine, LH rearward, below valve cover; 351/400 cid — centerline of engine block, full rearward; 460 cid — on top of engine rearward of carburetor; 302 cid — on engine block, LH lower side, near oil filter.
At what pressure does the oil pressure switch open?: The oil pressure switch opens with oil pressure over 6 PSI, which turns off the Oil Pressure Warning Indicator Light.
Where is connector C420 located and what does it look like?: C420 is on the toe board near the dimmer switch; it is a rectangular, brown, 2-terminal connector used in the Seat Belt Buckle Switch circuit.