Lima is not loading

Hello!

I'm having a problem with a Merc. W202 c250 turbo diesel.

The limakontroll lamp was lit in the cockpit.

So, the Lima (alternator) was replaced, but now I have a problem: the charging indicator light doesn't illuminate when the ignition is turned on.

The Lima charger is also not receiving a charge at the B+ terminal; it's only showing 12V.

I only have two connections on the Lima: B+ and D+.
When I connect the positive terminal (D+) and the negative terminal, I have battery voltage.

When the motor is running, I measure approximately 2.8V at terminal D+.

Can someone tell me what the normal voltage should be on the D+ terminal when the engine is running?

Hello!

Where do you measure the battery voltage when the D+ line is disconnected? Should it be connected to the main cable or to the alternator?

Disconnect the D+ sensor again and check the following, both with the ignition ON and the engine idling:
- Connect the D+ wire to ground -> The charging indicator light must illuminate!
- Open circuit in the positive (+) line -> The charging indicator light should not be illuminated!
- Open D+ line (positive voltage) in the air -> voltage measurement of 12V or 14V when charging.
- Open D+ connection in the air -> Start the engine, briefly increase the RPM slightly above approximately 3,000 RPM, and then the on-board voltage should be significantly above 12V (around 14V) in the subsequent idle state.

The voltage at the connected D+ terminal should be less than 1V when the ignition is ON, and approximately equal to the B+ voltage when the engine is idling.

Is the replacement alternator new, and does it really fit the vehicle 100%? Possibly, the "new" used item is defective again.
Is the terminal on the alternator also marked with "D+" and not with "DF" or "W"?
Does the ignition coil have voltage at the housing, both when the ignition is ON and when the engine is idling? Measure!

Best regards from Munich!

I've now replaced the alternator again with a different one, and everything is okay now.

I had connected a D+ wire and was getting 8V when the ignition was on, but the engine was not running.

@DieselBär30x thank you for your instructions!!!