Coolant temperature sensor?

Hello, I see what you mean, going through the wiring diagrams I've found a 2-wire sensor and a 4-wire sensor. I think one is for the computer, and the other type seems to be for the computer and for the gauge with a switch in it as well as a thermistor (sensor). Can you tell me the wire colors for the sensor on your car? The four wire colors on the harness plug. Some will be a solid color with a stripe down the side. I'm trying to find the correct sensor for you. There is either two coolant sensors for different reasons or there are two different designs. You can check the wiring with a multimeter if you'd like. I can walk you through it just to verify the wiring from the computer is okay.
If these 4 wire sensors colors are correct, solid yellow, solid purple, green with white stripe, and solid Dark Green (2nd diagram). Let me know.
And the third diagram, is that the sensor you are trying to replace?
One other thing, take a look at the tag on the inside of the door frame or on under side of the hood, there should be a build date, month and year (example 12/93 or 12/1993). It might be a change in design during the build year.

This is the OEM (Chevy) part number for the 4 wire Coolant Sensor/Switch (10137646). It might be something you could try calling a dealership and see if they carry this 4-wire sensor or if they know why there are different sensors listed. I will keep looking though.

This is a link to napa auto parts store. They have a 4-pin coolant sensor for $32.00. This looks like the correct sensor. This one has a switch for the coolant light, as well as a resistor for the gauge and another resistor for the engine computer input. Thats the difference between the 2 or 4 wire sensors. This could be a discrepancy due to where the car was built, the time of year it was built and possibly if the car is California emissions or not. But the link below will take you to the correct sensor, I don't know if you have a Napa near you, but you could order this online if needed.

https://www.napaonline.com/en/p/DEMTS10032?cid=paidsearch_shopping_dcoe_google&campaign=GSC-Fasteners-Hardware&campaign_id=10947735022&adgroup_id=107081865346&adtype=pla&gclid=CjwKCAjw4c-ZBhAEEiwAZ105RceXsb4vXwLsciPjh8TJC_zQezdM8GLpcEmZ-vL6uL6clr5lB3jzohoCuDMQAvD_BwE&gclsrc=aw.ds&

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Okay, great. I recommend getting the part from an auto parts store if you can. eBay parts may not be the best quality. We've seen a trend in parts over the last few years and the quality has declined significantly. And a coolant sensor is an extremely important input into the ECM (engine computer). It's the main sensor the computer will look at for its fuel strategy. Especially at cold start ups. If you want to check the wiring let us know. If the light is still on or the gauge is not working, after you replace the sensor. You can check the wiring with a basic voltage multimeter. Make sure when filling the coolant after the sensor replacement to allow the car to run while cold with the radiator cap off for a few minutes to help get the air out of the system. Just open the coolant system in the morning before the car has been started for the day so you don't get burned by the coolant, I say this from experience when I was starting out. Hot coolant in the face is very unpleasant. Hope all goes well...

https://www.2carpros.com/articles/coolant-temperature-sensor-cts-replacement

It is giving me a not compatible message for your car. I can understand why it would be discontinued. There' has been a lot of issues with getting parts for older vehicles as well as some newer ones. I'll search around a little bit more for you too. Check Rockauto com
Which part number did you find that was correct? And can you take a picture of the old sensor plug end? So, I know what the connector is going to look like.
Do you have a multimeter? Just a basic one?

Okay, I'm having a lot of trouble finding it as well. Even trying a 1992, there just aren't any in stock anywhere. Do you have AutoZone or Advanced Auto in your area? You could try calling them and give them the OEM number, tell them it's a 4-wire sensor. Maybe they can order it. Or a dealership, maybe online. They have them in stock for the 1994, but they all look 2 wire.

This is the diagram from a 1992, do you have another sensor below like this picture?
Interestingly, this is the OEM part number for the 1992, 10137646- same number as the 93'. On the tag on the underside of the hood say 'California Emissions Standards?

No, I don't think there will be a part number on it, does the hood tag say California Emissions? The 1994 part number is different.
If you have a multimeter that can check resistance, we can check the sensor
I would check the connector too, to see if there's any corrosion on the pins or in the connector.