I have a 1994 bmw 318i. Recently, the battery has been drained in the morning. We noticed a clicking noise coming from under the hood and pulled the fuel pump relay, which stopped both the clicking noise and the dead battery. We replaced the fuel pump relay (part number 61-36-1-729-004, but the car is still clicking, and the battery is still getting drained. Not sure what to do next. Thank you
Since the problem persists even after the relay has been replaced, it indicates a fault with the wiring system, Engine (Powertrain) and/or Transmission Control Module.
At the fuel pump relay, test the Brown/Green wire ( Terminal 85) for continuity to body. If cntinuity to body is present, unplug the PCM or TCM and retest. If problem goes away, the problem lies with the PCM/TCM, depending on which stops the relay from clicking.