Please help. 1997 C230 low coolant light came on. Checked the two sensors for washers and coolant level for voltage values. The coolant level sensor was faulty, replaced. Check water temperrture sensor , no problem. Also noticed that the water pump was noisy so replaced water pump. Low sensor light still remained. Checked for stored trouble codes with Autoxray and no stored codes were found. Eventually realised that the auxiliary cooling fan was not coming on and found water and corrosion signs at the plug to the aux. fan control module. Replaced the module and the low sensor light is still on. Any other suggestions?

Thanks, Stan.