Churtz

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

martysmartie

iTrader: (1)

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

tabetha

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

Churtz

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 )?

martysmartie

iTrader: (1)

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