The Cadillac DeVille from 1977 to 1982 represented the epitome of luxury and comfort during its era. Its electrical system, encompassing the fuse box and relay components, was integral to ensuring the vehicle’s smooth operation and reliability.
The fuse box in the 1977-1982 Cadillac DeVille housed various fuses designed to protect specific electrical circuits throughout the car. These circuits powered essential components such as the engine control module, lighting systems, climate control, entertainment features, and more. Fuses were critical as they would interrupt the electrical flow in case of an overload or short circuit, preventing damage to sensitive components.
Relays in the 1977-1982 Cadillac DeVille acted as electrically operated switches that controlled high-current circuits. They facilitated the precise activation and deactivation of functions like the starter motor, fuel pump, air conditioning compressor, and power windows or seats. Efficient power distribution by relays contributed significantly to the vehicle’s overall performance and reliability.
Regular inspection and maintenance of the fuse box and relays were necessary to ensure the 1977-1982 Cadillac DeVille operated smoothly. This included checking fuses for signs of wear or damage, ensuring secure relay connections, and promptly addressing any electrical issues that arose. Proper care of these components helped maintain the vehicle’s electrical integrity, enhancing safety and driving satisfaction for owners of the 1977-1982 Cadillac DeVille.
MUST READ: DYI – How to Check Car Fuses?
(1977-1982) Cadillac DeVille fuse box and relay with Diagram
WARNING
- Never replace a fuse with one that has a higher amperage rating.
- A fuse with a too-high amperage could damage the electrical part and cause a fire.
- On no account should fuses be repaired (e.g. patched up with tin foil or wire) as this may cause serious damage elsewhere in the electrical circuit or cause a fire.
- If a fuse blows repeatedly, do not keep replacing it. Instead, have the cause for the repeated short circuit or overload tracked and fixed.
- Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.
Cadillac DeVille 1977-1982 fuse assignment
- Cigar lighter / power outlet fuses in the Cadillac DeVille are the fuses №. 22 and 23 in the Engine compartment fuse box and fuse №65 in the Rear Underseat fuse box.
Year of production: 1977, 1978, 1979, 1980, 1981, 1982
Fuse Box
| No. | A | Circuit Protected |
| 1 | 5 | ’77-’79: Rheostat controlled instrument panel lights |
| 10 | ’80-’82: Front side marker, cornering and ash tray lights | |
| 2 | 3 | Cruise control, DFI brake switch (’80-’82) |
| 3 | 10 | ’77-’79: Cornering, side marker and opera lights, right door ash tray light, instrument panel ash tray light |
| 5 | ’80-’82: Rheostat controlled instrument panel lights | |
| 4 | 30 | ’77-’79: Circuit Breaker: Power windows and sunroof |
| 5 | 10 | Back-up lights |
| 6 | 20 | Air conditioner compressor feed, amplifier feed and relay coil feed, alternator telltale, ECC programmer and power module, alternator indicator and rear window defogger relay coil |
| 7 | 10 | Antenna switch feed |
| 8 | 20 | Turn signal lights |
| 9 | 25 | Opera lamps, tail lights, license light, rear side marker |
| 10 | 20 | Stop light switch, hazard warning flasher, ECC control head (’80-’82) |
| 11 | 20 | Oil pressure telltale, low brake telltale, coolant temperature telltale, fuel gauge, downshift switch, seat belt warning buzzer and light |
| 12 | 20 | Key warning buzzer, engine temperature telltale, glove box light, instrument panel cigar lighter and courtesy lights |
| 13 | 25 | ’77-’79: Automatic Temperature Control blower |
| 14 | 30 | ’77-’79: Circuit Breaker: Power door locks, power seats, horn, trunk release |
| 15 | 7.5 | ’77-’79: Radio |
| 10 | ’80-’82: Antenna relay coil | |
| 16 | 20 | ’77-’79: Electronic fuel injection |
| 17 | 20 | Body courtesy lights, cigar lighters |
| 18 | 25 | Windshield wipers and washer, washer fluid level telltale light |
| 19 | 25 | Rear defogger |
Circuit Breaker:
- Headlights (Twilight Sentinel) — Integral with headlight switch
- Windshield Wiper — Integral with windshield wiper switch
- ’77-’79: Sunroof — 25 amp. On body bracket at upper right corner of fuse block
- ’80-’82: Rear Defogger — Circuit breaker located on lower steering column cover reinforcement.
Fusible Link:
- Accessories & Body Feed — 16 gauge fusible link located in black/red stripe wire at starter
- Ignition — 16 gauge fusible link located in red wire at starter solenoid
- Headlights — 18 gauge fusible link located in yellow wire at starter
- Charging — 16 gauge fusible link located in red/white stripe wire at junction block
In-Line Fuse:
- Vanity Mirror — 2 amp. fuse located behind mirror
- ’77-’79: EFI Fuel Pump — 10 amp. fuse located left of fuel injection electronic control unit brown wire
- Theft Deterrent — 20 amp. fuse for lights located in yellow wire above radio. 25 amp. fuse for horn located in black/red stripe wire above radio
- ’80-’82: Trunk Lid Pull Down — One 20 amp. fuse is located behind right hand fabric rear end panel inside trunk
Passenger Compartment Fuse Box No.2 (’80-’82)
| No. | A | Circuit Protected |
| 1 | 3 | Fuel injector |
| 2 | 3 | Fuel injector |
| 3 | 3 | Fuel pump cranking circuit |
| 4 | 20 | ECS battery |
| 5 | 10 | MDA ignition |
| 6 | 10 | Fuel pump |
| 7 | 15 | ECS ignition |
| 8 | – | – |
Conclusion
For owners and enthusiasts of classic Cadillac DeVille 1977-1982, understanding the fuse box and relay systems is essential for vehicle maintenance. Regular inspection and maintenance of these components helped ensure the vehicle’s longevity and reliability, preserving its status as a symbol of Cadillac’s craftsmanship and innovation in the automotive industry during that era.
