Experience Dealership line mechanic on MG, Triumph, Jaguar for 15 years, Instructor in commercial mechanics school 2 yr. Product information manager for piston and valve manufacture, Instructor & hotline answer man for import car parts importer 15 yrs.
Organizations Associate member SAE
EAA member
Publications Import Car magazine
Education/Credentials ASE Master Auto with L-1 certification up to 2000
The ignition light is staying on so I expect the alternator is damaged.
Is it fixable or should I just get a new one.
It is a 79 Spitfire.
Thanks
Answer Hi Steve,
You may have damaged the alternator but run a test before you purchase one. Check the wires to the alternator first.
Turn the key on and note if the "Ign" light is on. If so put a volt meter across the posts of the battery and read battery voltage. Then start the engine and note if the "Ign" light went out. Also set the idle at about 1500 RPM and read battery voltage again.
If the "Ign" light went out and the 1500 RPM voltage is 13.8 to 14.5 volts the alternator is OK. If the light didn't go out and the voltage at 1500 RPM is close to what no run voltage was you did damage the alternator.
Connecting up a battery backwards can damage an alternator diode pack and/or a regulator. Most alternator shops can overhaul a Lucas alternator.
Howard
