Thread: Outside Temp adjustment
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Old Sep 28, 2008 | 06:39 AM
  #20 (permalink)  
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waldig
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Joined: Feb 2008
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From: VA
Talking Re: Outside Temp adjustment
Iam just writing here as I have not done this to my ambient air sensor but they are typically negative temperature coefficient thermistors, phew. The NTC sensor changes its resistance with temp and as it gets colder the readings are higher resistance.

If yours is reading too high, its resistive reading would be too low, less resistance than the chart would want in your computer.

The sensor pops into and out of the grill on the drivers side, its a black probe. There are two wires going to it and I would cut one wire, and then confirm that its readings go max negative or low temp.

Then locate a resistor like at radio shack for less than a buck and place it in series, connect it to the wire you cut with one end of the resistor going to each of the ends of the wire you cut. Start with about 1000 ohms and see if that is enough or if you need to add more. You cant add too much or two little resistance, it wont induce a failure, so experiment a bit and let us know.

If you have an old electronic item / radio; you can harvest resistor parts from there and the color codes ( to decode the value) are on the internet if you wanna learn something new.

If this does not work and goes potty, then no harm and no foul. Just re connect the wire where you cut it and your back to square one.

Enjoy Woody

PS. The resistance would alter the readings of the gauge, however the readings are not linear, less change at low end and more change at the high temp end. You are tweeking it to read more correctly at the range you use more often.

It is possible to make the sensor read higher by adding resistance in parallel (across the sensor) but the resistance would need to be higher like 10,000 ohms.

I did this to my ENGINE air temp sensor while debugging fault codes that made no sense and dealer could not interpret........this is why and when I went off the reservation and started getting into the pieces and part of the crossfire on my own. E W
 
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