92 s10 4.3 will start but dies after motor gets warm

I have replaced the fuel filter and I haven’t seen any change. The guy I bought it from I knew really well and he told me all the fluid levels were fine. I ended up checking the engine light using a jumper and I got error code 15. That code involves the coolant temp sensor. I went to check the sensor and it seemed clean, then checked the coolant reservoir and there was none. I then checked all the fluid levels. It had low oil and almost no brake fluid. After adding everything I needed it ran a little bit better. I also replaced the coolant sensor, but the plug didn’t match. I had to wire the new plug in and it had two wires instead of one so I looked at the plug and spliced only one of them and left the other alone. Someone my father works with said the other wire was a ground wire and that I needed to wire it to the negative side of the battery. After fixing the wiring I drove it a couple miles and the temperature was reading very hot and my check gages light came on. I pulled over and the engine felt very hot so I let it cool down. I’m not sure why all of the sudden it’s overheating. My father told me that it could be the water pump but I don’t know. I also realized that the previous owner kept a record of when he got gas, and the last time he got gas was back in June of 2018. So I’ve been driving it to work to use up all the old gas, but I also noticed the back left brake has a leak. I clamped off the back brake line because I know that you can run cars with front brakes only. I really like this truck and it only has 107,000 miles on it so I’m really hoping someone can help me figure out what is wrong with it.

Did you solve this? My uncle is having similar issues with his 1991 s10

Yeah, I had replaced the coolant sensor on the side of the engine, more specifically the passenger side. There is another one on the top of the engine, and that was the one that needed replaced. After replacing the correct one the engine light turned off and ran fine.

Thank you. I told him that I thought that it had 2 coolant sensors but he still has a hard time believing me since I'm female lol. I will let him know again. This time adding that it came from you.