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Dowie
17th January 2017, 12:07 PM
hi. quick question.
i had gauges fitted over the weekend. one of them is water sensor. on my thermostat i have 2 sensors fitted from factory. my auto elec used a larger blank next to those to fit new sensor.

he then tested both, and compared to factory sensor using ecu talk ? they are different by 6-7C. the higher the temps, the larger the temp difference between them.
sensors supposedy work off resistance, the higher the temps, the higher the resistance, in turn a higher temp is displayed at the gauge end.
so he he wasnt happy with results , and the factory sensor and redarc sensor were taken out and tested on bench in hot water and on bench both showed equal or near equal readings... once refited to car the temp difference widened again.

he suggested there may be resistance in the redarc loom from sensor to the control box. thus the difference between the factory reading and then redarc gauge reading.
i dont want to fork out 60 bucks for another sensor and/or loom.

my question is, if the 2 wire (green/black) cable from sensor to control box was damaged or kinked, could this cause a slightly higher resistance and there fore higher reading at control box end?

age has the better off me, and so has my aching back. i cant crawl under and over the car to invstigate so the mechanics and elecs have me by the knackers for labour work.

apologies for grammar , typing this off the tablet. car is a td42 intercooled.

Hodge
17th January 2017, 08:09 PM
Hey mate is this the same as yours ? I have a spare one here youre welcome to try ... Where in Melbournia are you.
Also if you think AND if your mechanic thinks cable maybe damaged , isnt he the one that fitted it? Therefore responsible for damaging it?

http://www.nissanpatrol.com.au/forums/images/imported/2017/01/93.jpg

Sent from S5

Rumcajs
17th January 2017, 08:35 PM
The thing with sensors especially resistive or thermistors is that you can't compare them equally as there are no apples vs choose >your fruit in here< especially when different brands are being used.

If there is suspect loom then how hard it is to read its resistance? Should be a walk in the park really. Any auto elec worth its fuse should be able to confirm that there is an issue with wiring. As for the kinked wire, unless there is physical dmage I don't think so, again multimeter will confirm that instantly....

Off the topic: not all temp senders are PTC or Positive Temperature Coefficient types (resistance increases with the temperature) indeed NTC units or Negative Temperature Coefficient types are better as senders for gauges....