Coolant level sensor/led problem

[andyf]

Hi all
I've just replaced my coolant level sensor on a 320i pre facelift cabbie; the old one was in extremely poor condition and indeed fell apart in my hands after removal. My problem is that the led light on the overhead consol still lights up...
The new sensor was specific to the car and identical to the one removed and being brand new I doubt it is faulty; isn't it more likely that the ageing wiring on my lovely is at fault?
Any help or advice gratefully received.
Andy

[Brianmoooore]

Short the two pins of the sensor plug together with a short piece of wire, and turn the ignition on. The LED should remain off. Pull the wire link out, with the ignition still on, and the LED should come on.
If the LED comes on with the link in place, check for a broken wire just where it enters the moulded plug.
There are two versions of the coolant level sensor around. One fits into the top of the coolant tank, such as on the E30, and the other fits into the bottom of a coolant tank, such as the combined tank and radiator used on the four cylinder E30s. No E30 was ever fitted with this sensor, but if you look at the bottom of a four cylinder E30 radiator, you will see the boss where it can be fitted.
I have been supplied with the wrong sensor on one occasion, and the effect is that the LED is on with the coolant at the correct level, and off when the coolant is low.

[andyf]

Problem solved!
Thank you for your help Brian