Woodtroll wrote:
I have one temperature gauge on my truck on a three-way switch that I use to monitor engine oil, transmission, and differential temps. It works just fine - whenever I want to check on the temps I just slide the switch through the three positions. However, my gauges are aftermarket (Autometer), and are electrical gauges (not mechanical) that use a sensor that varies the resistance on the ground wire that goes to the gauge.
All "electrical" thermal gauges use a sensor called thermistor (thermal resistor). These devices are only accurate for a limited temperature range. If you need accurate temps (+/- 1 degree) below freezing and above boiling, you will need 2 different sensor (and probably gauges). Of course companies like Autometer are not likely to publish their accuracy band.
I suspect that a very high temps (above 250F) the accuracy could be +/- 10 degrees F.
