ok i am trying to get my car back to mostly stock, it came with a aftermarket temp gauge. so i bought the oem water temp sensor, got it installed, traced down the dark green wire that plugs on it, but the pigtail was clipped off. the pigtail connector at autozone has two wires off of it??? is there another wire i dont know about?
thanks in advance.

 

that is probably the coolant temperature sensor for the ECM rather than the coolant sensor for the gauge. The CTS sensor has 2 wires, the coolant sensor for gauge has 1. go back and tell them you need the other one, and its only 1 wire. this sensor goes into the drivers side cylinder head between #1 and #3 cylinders.

 

It's just a female spade connector, crimp one on the end of the green wire, plug it up, and go!

 

Does the ECM need to be hooked up to the temp gauge? I bought an aftermarket gauge im mounting in my pillar pod and was going to run the new gauge right to the old spot of the stocker. Will this mess something up?

 

autozone and advance dont carry them, i got a new one off ebay. the idle of my car is alot better 89kicker with the stock temp sensor. id suggest putting it else where, mine had a annoying surging idle with the aftermarket one

 

So does the ECM read the temperature and make calculations/changes based off of it? I need to know because I am about to remove the stock sensor and plug in my autometer sensor.

My temperature gauge has been complete crap for years. It never gave accurate readings, I replaced the sensor/sending unit twice, and replaced the physical in-dash gauge twice. Nothing ever changed. It even used to get stuck upon start-up and I would have to open up my cluster and pop it back down. A few weeks ago my car started surging, overheated and stalled while still reading normal temp. when we were deadstopped in traffic for 15 minutes.