Target Audience:
Triumph Stag owners, classic car enthusiasts, mechanics specializing in British sports cars, restoration shops.
Value Proposition:
Provides essential, often hard-to-find, electrical documentation critical for maintaining and repairing the iconic Triumph Stag, a model known for its unique V8 engine and classic styling.
Essential Documentation:
Crucial for diagnosing and rectifying electrical issues, which can be complex in older vehicles. Enhances the usability and value of a Triumph Stag.
Electrical Components:
Headlights, taillights, turn signals, interior lighting, dashboard instruments, ignition system, starting system, charging system, fuel pump circuit, cooling fan circuit, wipers, horn, radio wiring, power windows (if equipped), seat belt warning system, hazard lights.
Wiring Diagram Types:
Complete chassis wiring harness diagrams, individual component wiring, fuse box layouts, relay locations, ground point identification.
Lighting System:
Detailed diagrams for headlights, sidelights, tail lights, brake lights, indicators, reverse lights, and interior illumination.
Instrumentation And Gauges:
Wiring for speedometer, tachometer, fuel gauge, temperature gauge, oil pressure warning light, ammeter/voltmeter, and warning lamps.
Charging System:
Diagrams covering the dynamo/alternator, voltage regulator, and associated wiring.
Starting System:
Wiring for the starter motor, solenoid, ignition switch, and neutral safety switch (if applicable).
Wiper Washer System:
Wiring for the windscreen wiper motor and washer pump.
Horn Circuit:
Diagrams for the horn, horn button, and relay.
Diagnostic Procedures:
Troubleshooting electrical faults, identifying common wiring issues, tracing circuits, understanding component functions.
Repair Procedures:
Guidance on repairing damaged wiring, replacing faulty components, understanding connector types and pinouts.
Fuse And Relay Identification:
Identification of fuse box locations, fuse types, ratings, and common relay functions.
Ground Point Identification:
Location and function of chassis ground points for electrical circuits.
Component Pinouts:
Diagrams showing the internal connections and pin assignments for various electrical components.
Depth:
Detailed, allowing for component-level diagnosis and repair of electrical systems. Essential for restoration and maintenance.
Wiring Color Coding:
Explanation of wiring color codes used throughout the vehicle's electrical system.
Circuit Tracing Guidance:
Methodology for tracing electrical circuits to diagnose faults.
Electrical Schematic Interpretation:
Guidance on how to read and interpret the complex wiring diagrams provided.
Engine Type:
V8 OHC (Overhead Camshaft)
Engine Code:
2.5 PI V8 (Standard)
Displacement:
2498 cc (152.4 cu in)
Bore X Stroke:
66.5 mm x 76 mm (2.62 in x 2.99 in)
Horsepower:
145 bhp (108 kW; 147 PS) at 5500 rpm (approx.)
Torque:
190 lb-ft (258 Nm) at 3500 rpm (approx.)
Fuel Delivery:
Lucas indirect fuel injection (2.5 PI - Petrol Injection)
Fuel Type:
Premium Unleaded Gasoline (95-98 RON)
Cooling Type:
Water-cooled
Oil Capacity:
6.5 liters (7.0 US quarts)
Ignition System:
Distributor with electronic ignition (later models) or conventional coil and points.
Crash Safety Era:
Designed in an era with less stringent safety regulations compared to modern vehicles. Structural integrity and passive safety features reflect 1970s standards.
Brakes:
Front: Ventilated disc brakes; Rear: Drum brakes.
Steering:
Power-assisted steering (standard).
Seat Belts:
Standard front seat belts, often inertia reel type. Rear lap belts.
Body Construction:
Body-on-frame construction with a steel monocoque body shell.
Oil Change Interval:
Every 5,000 miles or 6 months (recommended for classic cars).
Spark Plug Replacement:
Every 12,000 miles (or as per original specification).
Timing Belt Check:
OHC engine with timing chain, requires periodic inspection for tension and wear.
Engine Oil Specification:
20W50 or 10W40 (depending on climate, consult original manual for exact grade)
Coolant Specification:
Ethylene glycol-based antifreeze, mixed 50/50 with water.
Brake Fluid Specification:
DOT 4
Engine Reliability:
The V8 engine's cylinder head fixings and cooling system were prone to issues, leading to potential head gasket failure and overheating if not properly maintained. Over-boring and re-sleeving were common fixes for worn bores.
Electrical System Common Faults:
Degradation of wiring insulation, faulty switches, corrosion in connectors, and issues with the fuel injection system's electrical components are common.
Bodywork Corrosion:
Susceptible to rust, particularly around wheel arches, sills, door bottoms, and bulkhead.
Part Condition:
Many parts are no longer in production, requiring sourcing from specialist suppliers, used parts, or fabrication.
Marque History:
Triumph, a historic British marque, was known for its sporty and elegant cars. The Stag represented a move into the luxury GT segment for the brand.
Development Context:
Developed as a successor to the Triumph GT6 and Triumph 2000/2500. Designed by Giovanni Michelotti.
Key Design Features:
Four-seater convertible with a standard hardtop or optional soft-top. Distinctive chrome grille and flared wheel arches.
Production Years:
1970-1977
Production Volume:
Approximately 11,469 units produced.
Manufacturing Location:
Standard-Triumph factory, Canley, Coventry, England.
