Coolant Temperature sensor location?

For this issue you need to focus on the symptom and find out what system is at fault, for example the cooling system, electrical, or heating and A/C. I would verify the temperatures of the heater hoses as they enter the heater core at the bulkhead under the hood. The most common issue is a stuck open thermostat. Here is a guide that can you: https://www.2carpros.com/articles/how-a-car-heater-works

Bmdouble,

Thanks for quick reply I will check this out and get back on here when I can. Thank you!

You're welcome! Let us know if you need more help!

Okay. I just got done checking hoses. I let the car run and took it for a quick ride. Had nice warm heat while driving. Temperature gauge was still on C. I checked hoses and they are warm/hot to the touch.one at the firewall as well. So would this be a symptom of the thermostat being stuck open, therefore not letting gauge work properly even though i am getting heat?

Thanks,
Robert

Before replacing any parts we should have the powertrain control module (PCM) and the instrument cluster module scanned for codes. A scan tool will need to have bi-directional control also, meaning that there is a test (see attachment) for the gauge itself that will verify gauge operation as you control it from 0-100%. Other than that, the only sensor for temperature is the cylinder head temperature sensor. This sensor sends a signal to the PCM, then the PCM networks a signal to the instrument cluster module. I have also seen bad alternators, new and old, cause crazy electrical system issues. You can try to disconnect the alternator then start the vehicle and see if anything has changed.

Okay, thanks. I will try that. I may need to take it somewhere since I only have a obII scan tool and not sure it has that capability. I will unhook the starter again and rebook. I did notice and didn't mention and I apologize for that, when I changed alternators and hooked up negative at battery terminal I did see a bluish spark around alternator area. I just assumed it was just a charge in it as it is charging the the battery as it should with a volt meter. But I'll keep this post updated when I can do as suggested. Thank you for helping.

Yikes!!! Yes try that for sure, and get access to a bi-directional scanner if possible. Keep us posted!