Hey everyone. I was flushing my coolant today. I removed the airbox hose and found that I have some sort of electrical plug that has nothing plugged into it. I was wondering if you guys would know what goes into this plug? The car runs well and doesn't have any issues but I am thinking something is supposed to be plugged into this thing.

 

That is a retrofit coolant temperature sensor.

When the cars were built the temperature sensor was in the thermostat body. There was a recall or service program or something because the sensor would corrode and fail. The fix was to add a new sensor in the top hose: that's what you're looking at.

The thermostat was later redesigned to fix the temp sensor issue. If a new thermostat gets installed, they use the sensor in the thermostat instead and the retrofit one just gets abandoned in place like yours is.

 

https://www.northamericanmotoring.co...lant-leak.html

 

What Gubi said. Also those are known for leaking. Some vendor(s) sells a longer hose that eliminates that elbow. I just replaced the thermostat in mine with the newer version and did so.