The Cadillac Seville from 1986 to 1991 continued to uphold its reputation as a luxurious and technologically advanced sedan. Its electrical system, incorporating the fuse box and relay components, was pivotal for ensuring smooth operation and functionality.
In this generation, the fuse box in the Cadillac Seville housed fuses that safeguarded various electrical circuits throughout the vehicle. These circuits powered critical components such as the engine control module, lighting systems, climate control, and entertainment features. Fuses were designed to protect against electrical overload by interrupting the circuit if necessary.
Relays in the Cadillac Seville acted as electrically operated switches responsible for managing high-current circuits. They facilitated the precise activation and deactivation of functions such as the starter motor, fuel pump, air conditioning compressor, and power windows or seats. This efficient power distribution ensured reliable performance of the vehicle’s electrical systems.
Regular inspection and maintenance of the fuse box and relays were essential to uphold the Cadillac Seville’s operational efficiency. This involved checking fuses for signs of wear or damage, ensuring relay connections were secure, and promptly addressing any electrical issues that arose. Proper care of these components contributed to maintaining the vehicle’s electrical integrity, enhancing safety and driving satisfaction in the Cadillac Seville 1986-1991.
MUST READ: DYI – How to Check Car Fuses?
(1986-1991) Cadillac Seville 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 Seville 1986-1991 fuse assignment
- Cigar lighter / power outlet fuses in the Cadillac Seville is the fuse №.4.
Year of production: 1986, 1987, 1988, 1989, 1990, 1991
Passenger Compartment Fuse Box
| No. | A | Protected Component |
| 1 | 10A | Electric Height Sensor, Electronic Level Control (ELC) Compressor |
| 2 | 20A | Courtesy Lamps, Interior Light, Trunk Light |
| 3 | 10A | Antenna Relay |
| 4 | 20A | Rear Door Cigarette Lighter (’86-’89), Console Cigarette Lighter (’86), Chime Module (’88-’91), Fuel Door Release Switch (’86-’87), Glove Box Lamp (’86) |
| 5 | 15A | Central Power Supply |
| 6 | 20A | Electronic Level Control (ELC) Compressor Relay |
| 7 | 5A | ’90-’91: Programmer (HVAC) |
| 15A | ’86-’89: Auto Day/Night Mirror, Chime Module, Brake Switch (Cruise Control), Theft Deterrent Module, Theft Deterrent Relay | |
| 8 | 3A | Multi-Function Switch, Battery No Charge, Cruise Control |
| 9 | 7.5A | Programmer (AVAC), Rear Window Defogger Relay, Electric Height Sensor |
| 10 | 3A | Body Control Module (BCM), Overspeed Jumper (Saudi) |
| 11 | 10A | Radio |
| 12 | 25A | Windshield Wiper/Washer Switch |
| 13 | 15A | Trunk Release Switch |
| 14 | 10A | Courtesy Lamp Relay, High Beam Relay, Low Beam Relay, Retained Accessory Power (RAP) No.1 & 2, Twilight Headlight Relay, Twilight Park Light Relay |
| 15 | 15A | ’90-’91: Twilight Park Light Relay, Left Switch |
| 20A | ’86-’89: Twilight Park Light Relay, Left Switch | |
| 16 | 20A | Brake Switch (Stop Lamps), Turn/Hazard Module (’86) |
| 17 | 10A | Radio Power, Keyless Entry Module (’90-’91) |
| 18 | 10A | Turn/Hazard Module, Fuel Tank Unit, Air Bags (DERM (’90-’91)), Gear Selector Switch, Body Control Module (BCM), Information Center, Keyless Entry Module (’90-’91), Auto Door Lock Module (’86-’89), Seat/Mirrors Memory Module (’87) |
| 19 | 15A | ’90-’91: Air Bags (DERM), Dual Sens |
| 15A | ’89: Parking Lights, Front/Rear Side Markers, Opera Lamp, Tail Lights, Engine Compartment Lamp, License Plate Lamp, Instrument Panel Cluster, Trailer Connector | |
| 10A | ’86-’88: Parking Lights, Front/Rear Side Markers, Opera Lamp, Tail Lights, Engine Compartment Lamp, License Plate Lamp, Instrument Panel Cluster, Trailer Connector, Telephone | |
| 20 | 30A | ’90-’91: Rear Window Defogger Relay |
| 25A | ’88-’89: Bose Amplifier | |
| Circuit Breaker | ||
| 21 | 10A | Low-Beam Lights, Twilight Headlight Relay, Left Switch |
| 22 | 20A | High-Beam Relay |
| 23 | 30A | Power Seats, Door Lock Relay, Radio Amplifier (’86-’87), Seat/Mirrors Memory Module (’87) |
| 24 | 30A | ’90-’91: Retained Accessory Power (RAP) Relay |
| 30A | ’88-’89: Horn Relay | |
| 30A | ’86-’89: Rear Window Defogger Relay, Horn Relay | |
| 25 | 30A | ’86-’89: Retained Accessory Power (RAP) Relay No.2, Accessory Relay (’86) |
Passenger Compartment Relay Box
| No. | A | Circuits protected |
| 1 | 10A | ’90-’91: VCC Brake Switch, Chime Module, Theft Deterrent Module, Auto Day/Night Mirror |
| 10A | ’86-’89: Power Mirror Heater | |
| 2 | 15A | ’90-’91: Fuel Pump Relay, Oil Pressure Switch |
| 2A | ’86-’89: Cellular Phone Transceiver | |
| 3 | 10A | ’90-’91: Fuel Door Release Switch |
| 20A | ’88-’89: Fuel Door Release Switch | |
| ’87: Seat/Mirrors Memory Module | ||
| 4 | 20A | Trunk Pull-Down Unit |
| 5 | 25A | ’90-’91: Amplifier Relays (Delco Bose) |
| 6 | – | – |
| 7 | 10A | ’90-’91: ABS Module, Computer Command Ride (CCR) Module, Heated Windshield Module |
| 8 | 3A | ’90-’91: Body Control Module (Pin 1C9), Diagnostic Energy Reserve Module (DERM) |
| Relay | ||
| R1 | ’86-’87: Radio Amplifier | |
| R2 | ’86-’89: Electronic Level Control (ELC) Compressor | |
| R3 | High Beam | |
| R4 | Retained Accessory Power (RAP) No.2 (Power Window, Sunroof) | |
| R5 | ’90-’91: Fuel Pump | |
| ’86-’89: Fuel Tank Unit, Engine Control Module | ||
| R6 | Retained Accessory Power (RAP) No.1 | |
| R7 | Twilight Crank | |
| Rear Window Defogger, Power Mirror Heater | ||
| R8 | Twilight Headlight | |
| R9 | Low Beam | |
| R10 | Twilight Park Light | |
Engine Compartment Fuse Box
| No. | A | Circuits protected |
| 1 | 10A | ’90-’91: A/C Compressor Clutch Relay |
| 10A | ’86-’89: Fan Control Module, A/C Compressor Clutch Relay | |
| 2 | 15A | ’90-’91: Cooling Fan (B), Low Refrigerang Switch |
| 15A | ’86-’89: A/C Compressor Clutch Relay | |
| 3 | 10A | ’90-’91: EGR Solenoid, Auto Transaxle, Canister Purge Solenoid, P/S Pressure Switch |
| ’88-’89: Engine Control Module | ||
| 10A | ’86-’87: Air Switch Solenoid, Air Diverter, EGR Solenoid, Canister Purge Solenoid, Power Steering Cutout Switch | |
| 4 | 20A | ’90-’91: Horn |
| ’86-’89: Fuel Pump Relay, Engine Control Module, Oil Pressure Sender | ||
| 5 | 7.5A | ’86-’89: Fuel Injectors |
| 6 | 7.5A | ’86-’89: Fuel Injectors |
| 7 | 10A | ’90-’91: Powerttrain Control Module (PCM (Pin A6) , Pass Key Decoder Module |
| ’86-’89: Engine Control Module | ||
| 8 | – | ’86-’89: Body Computer Module, Electronic Brake Control Module |
| Relay | ||
| R1 | – | |
| R2 | – | |
| R3 | ’90-’91: Cooling Fan (B) | |
| ’88-’89: Horn | ||
| ’86-’87: Fan Control Module | ||
| R4 | ’88-’91: A/C Compressor Clutch | |
| ’86-’87: EFE Heater | ||
| R5 | ’90-’91: Cooling Fan (C) | |
| ’88-’89: Fan Control Module | ||
| R6 | ’90-’91, ’86-’87: Horn | |
| R7 | ’90-’91: Cooling Fan (D) | |
| R8 | – | |
| R9 | ’86-’87: Courtesy Lamps | |
| R10 | ’86-’87: Horn | |
Fusible Link (’90-’91)
- RED (RUST) – Cooling Fan Relays
- ORG (RUST) – Pass Key Decoder, Powertrain Control Module (PCM)
- RED (RUST) – Ignition Switch, Fuse No.: “5”, “14”, “17”; Fuse (Passenger Compartment Relay Box) No.: “5”
- RED (RUST) – Theft Deterrent Module, Fuse No.: “1”, “20”; Fuse (Passenger Compartment Relay Box) No.: “3”
- RED (RUST) – Fuse No.: “15”, “21”, “22”
- RED (RUST) – Fuse No.: “23”
- ORG (RUST) – Power Module, Fuse No.: “16”
- RED (RUST) – Ignition Switch, Retained Accessory Power (RAP) Relay No.1, Retained Accessory Power (RAP) Relay No.2
- RED (BLK) – Brake Modulator
- RED (BLU) – Brake Modulator
- RED (RUST) – Heated Windshield Module
Fusible Link (’88-’89)
- RED (ORG) – Power Module
- RED (ORG) – Cooling Fan Relays
- RED (ORG) – Fuse (Engine Compartment Fuse Box) No.: “2”
- ORG (ORG) – Engine Control Module
- RED (ORG) – Fuse (Passenger Compartment Relay Box) No.: “2”
- RED (ORG) – Ignition Switch, Fuse No.: “5”, “14”, “17”, “20”
- RED (ORG) – Theft Deterrent Module, Fuse No.: “4”, “24”; Fuse (Passenger Compartment Relay Box) No.: “3”, “4”
- RED-WHT (ORG) – Fuse No.: “15”, “21”, “22”
- RED-BLK (ORG) – Fuse No.: “23”
- RED (ORG) – Fuse No.: “18”, “25”
- RED (ORG) – Ignition Switch, Retained Accessory Power (RAP) Relay No.1
- RED (RED) – Brake Pump Relay
- RED (RED) – ABS Main Relay
Fusible Link (’86-’87)
- YEL/RED (ORG) – Power Module, Cooling Fan Relay (B)
- RED (ORG) – EFI Relay
- RED (ORG) – Fuse (Engine Compartment Fuse Box) No.: “2”
- ORG (ORG) – Engine Control Module
- RED (ORG) – Fuse (Passenger Compartment Relay Box) No.: “2”
- RED (GRY) – Ignition Switch, Fuse No.: “5”, “14”, “17”
- RED (ORG) – Theft Deterrent Module, Fuse No.: “4”, “24”; Fuse (Passenger Compartment Relay Box) No.: “4”
- RED (ORG) – Fuse No.: “16”, “25”
- RED-BLK (ORG) – Fuse No.: “23”; RED – Fuse (Passenger Compartment Relay Box) No.: “3”
- RED (ORG) – Ignition Switch, Retained Accessory Power (RAP) Relay No.1
- RED-WHT (ORG) – Fuse No.: “15”, “21”, “22”
Relay Location (’90-’91)
Rear Window Defogger Relay, Courtesy Lights Relay, Theft Deterrent Relay, Sound System Relay, Panel Lights Inhibit Relay, Retained Accessory Power (RAP) Relay, Turn Signal Flasher Relay, Park Lights Relay, Foglight Inhibit Relay, Electronic Level Control (ELC) Relay
Starter Enable Relay, Retained Accessory Power (RAP) Relay, Retained Accessory Power (RAP) Circuit Breaker
ABS Main Relay, ABS Pump Relay, ABS Main Fuse
Starter Interrupt Relay, Theft Deterrent Relay
Conclusion
For owners and enthusiasts of classic Cadillac Seville 1986-1991, 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.
