- Joined
- Dec 8, 2018
- Messages
- 61
1975 Commando MK III:
First test:
- Leads from the alternator disconnected
- Engine running at 3000 RPM
- Voltage across leads =~ 25 VAC
Second test:
- Almost new battery
- Alternator leads plugged in
- Engine stopped
- Voltage at power outlet =~ 12.8 V
Third test:
- Engine at 3000 RPM
- Voltage at power outlet =~ 12.5 V
Conclusion:
The battery isn't getting charging voltage (above 14, or so). In fact, the voltage at the power outlet goes down with the engine running. I assume the voltage at the battery is also about the same, 12.5 V.
Can anyone guess what's going on or have suggestions for other tests?
First test:
- Leads from the alternator disconnected
- Engine running at 3000 RPM
- Voltage across leads =~ 25 VAC
Second test:
- Almost new battery
- Alternator leads plugged in
- Engine stopped
- Voltage at power outlet =~ 12.8 V
Third test:
- Engine at 3000 RPM
- Voltage at power outlet =~ 12.5 V
Conclusion:
The battery isn't getting charging voltage (above 14, or so). In fact, the voltage at the power outlet goes down with the engine running. I assume the voltage at the battery is also about the same, 12.5 V.
Can anyone guess what's going on or have suggestions for other tests?