Bulkhead Workshop › Land Rover models › Land Rover Series III 2.25 diesel › Workshop guide › Heater plug & starting check

Land Rover Series III 2.25 diesel: heater plug & starting check

Electrical · Series III (1971–85) · 1971–1985

How often: every 12,000 mi or year, whichever comes first. Series diesel heater plugs are wired in series: one failed plug stops them all working.

Work safely: support the vehicle on axle stands, never a jack alone; let it cool first. Check figures against your workshop manual. You do this work at your own risk.

Parts

4 × Heater plugs (as needed) (series-wired type for this engine)
Heater plug resistor / warning coil (if failed)

Tools

Test lamp or multimeter
Spanners

Step by step

With the switch on 'heat', check the dash warning coil glows red within 20–40 seconds.
If it does not glow, check each plug in turn with a test lamp across its terminals. Because they are in series, one open-circuit plug kills the whole circuit.
Clean the busbar links and connections; corrosion here causes most failures.
Check battery condition. Series diesels need a strong battery and clean earth straps to start in cold weather.

More Land Rover Series III 2.25 diesel servicing

Engine oil & filter change every 3,000 mi or 6 months
Clean oil-bath air cleaner every 6,000 mi or year
Fuel filter change & bleed every 12,000 mi or year
Drain fuel sedimenter / water trap every 6,000 mi or 6 months
Check & adjust valve clearances every 12,000 mi or year
Injector test & service every 24,000 mi or 2 yrs
Fan / auxiliary belt check every 6,000 mi or year
Coolant drain, flush & refill every 2 yrs
Grease propshafts & nipples every 3,000 mi or 6 months
Check swivel housing oil & seals every 6,000 mi or 6 months
Change swivel housing oil every 12,000 mi or year
Check gearbox, transfer & axle oil levels every 6,000 mi or 6 months
Change gearbox & transfer box oil every 12,000 mi or year
Change front & rear axle oil every 12,000 mi or year
Steering box, relay & joints check every 6,000 mi or year
Adjust drum brakes & handbrake every 6,000 mi or 6 months
Inspect brake shoes, cylinders & hoses every 12,000 mi or year
Brake & clutch fluid change every 2 yrs
Leaf springs, U-bolts & shackles every 12,000 mi or year
Wheel bearing play check every 12,000 mi or year
Chassis & bulkhead inspection, rust-proofing every year
Annual safety inspection every year
Monthly walk-round checks every month

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