I can't find the damn thing. I know it connects to passenger side of block (thanks to you guys), but I cant find that blue wire. Where does it exit the firewall?

Also, if the temp sensor is on the passenger side what is the other one on the drivers side?

 

Which temperature sensor are you speaking of?

 

the one between spark plug 8 and 6. I think that is the one I need. There is another sensor between plugs 1 and 3 but I dont know what that one is.

 

On my 1989 the sensor between 1 & 3 on the drivers side is the aux.fan sensor/switch. It turns the pusher fan on and off.

 

The only sensor in the right side of the block is the knock sensor. On my car the KS takes a blue wire. 1984 and 1985 cars have a temp switch in the right side head, between the #6 & #8 spark plugs, and the IP gauge sender/sensor in the left side head, between the #1 & #3 spark plugs. 1986 through 1989 have the locations of the fan switch and gauge senders swapped. Since there is no mention of what YEAR, that is the best I can do.

I am CFI-EFI, and I approve of this message.

RACE ON!!!

 

Your are looking for a green wire, not a blue wire. It should have a spade type connector on the end of the wire. It runs toward the rear right side of the engine and into the firewall harness. You may have to get the car up on ramps or stands to look from underneath. I gave you a pic of the sender and wire in your other thread.

Looks like a 87 C4 from the profile.

 

Just wondering if your temperature guage works? If it does, disconnect one of the connectors (on either side of the block) and see if the gauge cotinues to work or if it goes off. Then you at least know what one sender is and it should be a resistence type sensor as it measures temperatures. It should be referred to as the guage temperature sender and it goes to the cluster (via the battery area bulkhead connector). I hate to mention this! Of course there is another temp sensor in front of engine manifold and I think the ECM is the only thing that uses it to keep engine running correctly. So, just forget this one but know it exists but normally adds to many of person's getting mixed-up.

The last sensor (side varies between years) is called a cooling fan sensor and it will respond to heat by being "open" or "closed". If you were able to determine the gauge sender above then you know that the other is COOLING FAN SENDER. When your temperature gets to a predetermined temperature, it grounds itself and sends signal to ECM via the battery area "bulkhead" connector. This fan sender can be purchased to close at different temperatures like 180, 190, 200 degree . . . I think the one in my 84 closes around 229 degrees and the one I bought for my 88 closes at 180 degrees--that is when the fan comes on. So, when your cooling fan comes on look at your temperature guage and see if they are in sync.

All my information may have helped or it has just added more confusion? Or, you have already solved your problem.

 

The wire for temp sender is in the loom with starter wires. Look around your solenoid for an extra wire.