Hi John,
Sorry, yes Engine Coolant Temp Sensor. Car was way down on power and not fuelling right. There is 2 pins on sender. One has the blue and white wire connected with black plastic connector. there is a second wire which has been hanging loose since I got the car. It is a black wire with red spade connector. I did connect it to the second pin but it didn't change anything in the dash or or with the dials. Would I be best to leave well alone? lol

Hi John, if it's no problem could you email me a pic or 2 of the left side of your 7a. I'm having problems with my oil pressure sender. I want to check if the wiring is right. I changed the ECTS on bulk head last night and since then my oil pressure gauge has dropped to 0 on idle and oil pressure warning light flashes. Car is going perfect though. There is only one wire connected to oil pressure sender unit and one pin is free.
Any help would be great.