Brand new 16/17ACR 55 Amp/Hr alternators are offered for outright sale with no exchange necessary. Boasting up to 30% more power over standard units, making them ideal for cars where electronic upgrades demand a higher output from the alternator. Alternators are supplied complete with fan, pulley and ACR plug retaining clip.
MGOC Spares also stock the parts to convert earlier MG models fitted with dynamos to alternators. See Kit ALT1.
Ignition Warning Light Trouble Shooting:
At low RPM the alternator requires a voltage supply from the battery via the ignition light circuit to energise the stator within the alternator in order that the alternator can produce a charge. Because a conventional filament bulb is effectively a resistor it can pass voltage from the battery to the alternator to energise the stator, a Light Emitting Diode (LED) however passes current one way only i.e it cannot pass voltage from the battery to the alternator, so the circuit cannot energise the stator and create a charge. If an LED is fitted within the warning lamp circuit the ignition warning light will stay on and the alternator will not charge below 2500rpm. When the rpm is raised above 2500rpm the alternator self-energises dispensing with need for supply via the ignition warning light circuit and the LED will go out. The issue has only recently come to 'light' with owners altering their dash bulbs to LED.
Alternator trouble shooting:
Many perceived MGB alternator failures are just poor connections or faulty grounds:
• Clean all the spade connectors on the back of the alternator.
• Ensure the thick brown wires (main positive output) are securely attached and carrying battery voltage.
• Check the main engine earth strap (braided cable) running to the chassis; heavily corroded or clogged earth straps cause significant voltage drops.
• Ensure the drive belt isn't slipping or loose.