N54 Coolant pump electrical issue.

[mikeypx82]

I was driving home a few weeks ago and got a warning on the navigation display that the car was getting hot and to drive moderately followed by a red warning saying that the car overheated and to pull over. Thought it was strange since the oil temp hadn’t reached operating temp yet. I let it cool down and after doing some troubleshooting, determined that the pump stopped working.

I had an aftermarket pump installed about 9 months ago because the original BMW pump was leaking. I figured the pump just died because it was a cheap aftermarket pump. I bought another pump and had a mechanic install it, still didn’t work.

I checked the fuse 37 and the big 50amp fuse next to the DME are both good. Used my multmeter to test the connector at the water pump. On my car pin 1 is switched power at fuse 37, pin to is BSD, pin 3 is constant power from the 50 amp fuse and pin 4 is ground.

Everything checked out except for pin 1. I’m getting continuity to ground on pin 1. I ruled out the thermostat. I know pin 1 on the pump also connects to the thermostat. I unplugged the thermostat and it’s still shorted to ground. I checked as much as of the wire as I could for damage but couldn’t find any. Is the orange wire at pin 1 of the coolant pump supposed to be grounded when the ignition is off?