Found a bypassed sensor?

Having picked up a MGF last November and just got it out of the garage due to funds and lots of bits and pieces needing replaced, I came across a connector in the engine bay which was taped up. Being curious I found a loop of wire across the 2 wire connector. So I started the engine and pulled the wire out. The warning lamp for overheated engine bay comes on and goes out when the wire is replaced. I would, obviously, like to have the proper sensor fitted and was wondering if anyone can help with where it should be and where to get a new one as it's been bypassed for a reason.....
It's a 98 K series and I found the wiring on the far right hand side beside the ECU.

Thanks, Keith

Itsmeontbar;15620 wrote: Having picked up a MGF last November and just got it out of the garage due to funds and lots of bits and pieces needing replaced, I came across a connector in the engine bay which was taped up. Being curious I found a loop of wire across the 2 wire connector. So I started the engine and pulled the wire out. The warning lamp for overheated engine bay comes on and goes out when the wire is replaced. I would, obviously, like to have the proper sensor fitted and was wondering if anyone can help with where it should be and where to get a new one as it's been bypassed for a reason.....
It's a 98 K series and I found the wiring on the far right hand side beside the ECU.



Thanks, Keith

Hi Keith, :welcome2:
What colour are the wires on the plug? Is it like this?

If so, it is the Engine coolant temp sensor plug.(ECT)

Should be here:- Photo courtesy of CJJ

David, is it not the Ambient Air Temprature (AAT) sensor that controls the engine bay cooling fan in the air duct? this sensor is located just above the inlet manifold (i am telling you when you know where it is!!) i know someone who bought a 1999 MGF with suspected HGF for £400 and turned out to be this sensor had failed, circuit had been bypassed so that warning light didnt come on but fan didnt work. he is now selling a full headgasket set, cambelt and tensioner. Sold the F for £1400, jammy bugger.

Bryan Young;15625 wrote: David, is it not the Ambient Air Temprature (AAT) sensor that controls the engine bay cooling fan in the air duct? this sensor is located just above the inlet manifold (i am telling you when you know where it is!!) i know someone who bought a 1999 MGF with suspected HGF for £400 and turned out to be this sensor had failed, circuit had been bypassed so that warning light didnt come on but fan didnt work. he is now selling a full headgasket set, cambelt and tensioner. Sold the F for £1400, jammy bugger.

It could be, Bryan. That was my first thought, but when Keith said it was near the ECU, I had second thoughts.
The AAT is here, near the expansion tank.

Do you have a photo of it? That would help.