I am trouble shooting my central locking system (1987 300E) and it passes the voltage tests with the exception of the passenger door lock.

But I cannot get the vacuum pump to operate using the car's electrical system as designed. I can however get the central locking system to operate if I run 12 volts directly from the car's battery to the pump motor and then use a second hot line to serve as a control to activate the power at the pump motor.(lock the system) I can then reactivate the motor (unlock the system) by using a ground wire as a control.

Both my connectors : three pin and two pin have 12 volts at the pump assembly.... but the system will not operate from that voltage.... it operates only from direct battery voltage.

I checked the amperage of the two pin connector (power to pump motor) and it has only .04 amps at 12 or better volts. It seems to me that there may not be sufficient amperage in the cars central locking system to operate the system.

Does anyone know what the problem might be?

Also I cannot find the connection X48F. My documentation says that it is supposed to be at the Right Rear Door Sill Area. Does anyone know what this junction/connector looks like and where it is located on an 87 300E?

Smiles.



[Edited by ejsharp on 05-07-2001 at 04:20 PM]

__________________
Earl



1993 190E 2.3
2000 Toyota 4x4 Tundra