Wolf_n_Kat wrote:
Griff in Fairbanks wrote:
On the case of engine temperature, the sensor has a wax/plastic plug that melts and solidifies over a range of temperatures, increasing or decreasing resistance in the circuit. Over time (decades), the plug loses its ability to respond to temperature changes.
Okay, 'my' take-away from this? (and thanks for that tid-bit of information, Griff!! Something REALLY nice to know when troubleshooting sensor-dependent circuits!) If you don't know how old a sensor is and if/when it was last replaced, it 'might' be a good idea to replace it anyway.
Actually, I'd check the wires and connections on both the gauge and ground sides of the sensor first. More often, I find problems with the circuits themselves rather than the sensor or gauge. That said, the sensor are relatively inexpensive and worth replacing on older engines, especially if working on it gives you easy access to the sensor.
In the case of engine oil pressure, instead of using an OEM sensor, use a late model sensor. On newer vehicles, the sensor contains both a switch and variable resistor, giving you the ability to have both an oil pressure gauge and indicator light.
I don't have the part numbers handy for that upgrade but will find them if there's enough interest. (Ask Leeann what she thinks of the upgrade ... she installed it on her motorhome.)
