Hi there, just a quickie. A while ago the cooling fan on my 190e 1989 was not coming on at all no matter what temperature. I understand that it is supposed to kick in at around 100 degrees. I was advised to change the (dont know what its real name is) temperature sender unit!! You know the brass thing that screws in on top of the engine. Well I have done that now and it still isn't working. I have tried touching the contacts together and the fan works when it is given direct power. Are there any other things I should check for? Thanks.