sensor feedback

Hey folks,

Yesterday when I was sitting in my car, looking at the idiot lights and wishing my car would've come with tach and center gauges, I figured that mostly I'd love to have a better indication of the temperature and oil pressure, the tach is not so much required.

Then I thought of maybe replacing the single bulb behind the idiot lights with a set of lights running from green to red. Apart from the electronics required to make something like that, would any changes be required on the sensor end of things? Or is the required feedback from the sensor already available but simply not used in an idiot-lights-cluster?

Cheers,

Vincent.

I believe the sensor is basically a binary switch/sensor.

+1, it's either on or off. You could run it through a relay so you could use it to switch leads or polarities of a bi-color red-green LED.

http://www.dialightsignalsandcomponents.com/Assets/Brochures_And_Catalogs/Indication/PMI_new/Dialight_PMI_data_606_Sep2019.pdf

So a car equippedwith gauges has different sensors? I’d be OK with adding or changing the sensor, just have no idea what’s in there now...

Yes, the sending units are different for gauges and indicator lamp systems.

Yes, the oil pressure and temperature sensors for non-gauge cars are normally off, and switch on (provide a ground) only when the oil pressure drops below a pre-set value or the temperature rises above a pre-set value.

The sensors in gauge equipped cars vary the resistance to ground. Oil pressure sensors are electro-mechanical, with a diaphragm moving the wiper on a variable resistor. The temperature sensor is electrical, using a thermistor to change the resistance to ground.

Right. I think I will be putting the service manuals to good use this Christmas then.

Cheers!

V.

Vinnie, Here is what I did. I have the "idiot lights" and wanted to add gauges but keep the idiot lights. I added a T to the oil sensor fitting to retain the original sensor and to add the new sensor for the after market gauge. For the Temp sensor I didn't have to add the T as I removed all of the emissions stuff from the vehicle and this left a port for the additional temp sensor. I just ran new wires for the gauges so as not to cut into the original wiring harness.