Jaguar Repair: xk120 overcharging, load voltage, high drain

Question
1953 xk120 Generator output good.1500 rpm up the ammeter will go to 20-25 amps.Headlights will bring it down to about 2 amps.Changed regulator and batteries. Still overcharges.What is wrong?

Answer
Hi Henry,
You are quoting amperage. Amperage is 100% dependent on load. Voltage is the push (charging system) What is the voltage? It should not be more than 13.8 to 14.5 volts. If the voltage is not over 14.5 volts than is it not over charging. If the amps are high, the demand it high. If the batteries are fully charged than you have a high drain somewhere for the amps to go high on a fully charged battery pack. If the new batteries are low, than the amperage rate will normally be high until the batteries get fully charged.
Howard