1518870 Diode | Genuine Volvo Penta Part

🔧 Product Description

A genuine Volvo Penta electrical diode used in selected engine-control and general wiring systems. The diode permits current flow in one direction and blocks reverse current, providing circuit isolation or suppression according to the harness design. The part is confirmed in KAD44P and KAMD44P-A general electrical-system diagrams and is catalogued in product group 2300, function group 9729. It is a harness diode rather than an alternator rectifier diode.

🚤 Compatibility

• Engine Family: MD, TMD, AD, AQAD, D, TAMD, BB, HS, AQD, KAD, KAMD
• HP Range: Approximately 260 HP
• Year Range: Approximately late 1990s - early 2000s

Full model list at the end of this description.

⚙️ Key Features

• Genuine Volvo Penta OEM part number 1518870
• System group: Industrial and Marine Equipment
• Net weight approximately 0.020 kg
• Fits MD, TMD, TAMD, AD, AQAD, AQD, D, KAD and KAMD series marine engines, plus 740A/BB740A and HS1A units
• Supplied as an individual electrical component
• Engine type: Volvo Penta electronically managed inline 6-cylinder marine diesel electrical system

🔌 Function

The diode permits electrical current to flow in one direction only, protecting circuits from reverse current and voltage spikes. In marine engine installations it is typically used within charging, alarm and relay control circuits to isolate and direct current between components.

⚠️ Common Signs of Failure

• Charging or warning circuit faults with no obvious wiring damage
• Warning lamps or alarms staying on, flickering or failing to illuminate
• Battery discharge caused by reverse current leakage through a shorted diode
• Open-circuit reading when tested, giving no continuity in either direction
• Visible scorching, cracking or heat discolouration of the diode body or leads

🛠️ Service Notes

• Isolate the batteries before working on the circuit and note which way round the diode is connected — a diode passes current one way only, and fitting it reversed will either stop the circuit working or leave something live that should not be
• Refit it in the original position with the same mounting and insulation, keeping any heat-shedding contact the original had
• Make the connections cleanly and keep the body cool while soldering or crimping, then protect the joint against damp as the original was protected
• Test a suspect diode out of circuit rather than in it, and look for why it failed — a diode usually goes because of a surge, a short or a charging fault elsewhere

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging

🔎 Full Model Compatibility

Typically suits:

• Volvo Penta AD31, AD31B, AD31D, AD31D-A, AD31XD
• Volvo Penta AD41B, AD41D, AD41A, AD41BJ
• Volvo Penta TAMD31A, TAMD31B, TAMD31D
• Volvo Penta TAMD41B, TAMD41D, TAMD41A
• Volvo Penta TMD31A, TMD31B, TMD31D
• Volvo Penta TMD40A, TMD40B, TMD40C
• Volvo Penta TMD41A, TMD41B, TMD41D
• Volvo Penta AQAD40B, AQAD40A
• Volvo Penta D41B, D41D
• Volvo Penta TAMD40A, TAMD40B
• Volvo Penta AD30A
• Volvo Penta AD40B
• Volvo Penta AQAD30A
• Volvo Penta AQD40A
• Volvo Penta BB740A
• Volvo Penta HS1A
• Volvo Penta KAD44P
• Volvo Penta KAMD44P-A
• Volvo Penta MD30A
• Volvo Penta MD31A
• Volvo Penta MD40A
• Volvo Penta 740A
• Volvo Penta TAMD30A
• Volvo Penta TAMD42B
• Volvo Penta TMD30A