hi all.

a quick question on the temp sensor for the gauge on a mk4 fiesta. it is a single pin connection.

i have fitted a 2.0 blacktop in there and the only place i can now mount the sensor is too far away for the wiring to reach. Can i simply extend the wiring or is there something special in there?

dont really know how this type of sensor works as its just a bolt thread for the wiring plug to clip on.

Any help appreciated.

Thanks,
Matt

 

No nothing special, you can just simply extend the wire, the senders resistance changes with temperature (So essentially a thermistor), as the temperature increases the resistance decreases hence giving you a reading on the gauge and vice versa and so the reading decreases when cooler as the resistance has increased.

Martin

 

As above extend at will, it will have a slight effect on the reading but nothing you'd be able to notice from the length extension needed on a car.
Most sensors are as stated in operation, known as NTC(negative temperature co effecient) , but you do also get PTS(positive) ones.
tabetha

 

Out of curiosity...

Does this sensor have a live from the dash, and the sensor acts as a thermo resistor to the ground ( engine it's screwed into )?

 

There is a switched feed which goes to the gauge and the earth for which is connected to the sender, it's works as I explained above. Basically as temperature increases the resistance decreases hence giving you the reading (NTC). This is a fairly old hat now, especially with modern cars/dashes most if not all are controlled by ECU which are far more accurate.

Martin