duanejangula

I have a 1987 Camaro iroc-z with 5.7 liter TPI.
How many cooling temp sensors (cts) are there and where are they located???
Reason I'm asking is to diagnose my passenger side electric fan is not working. My a/c also does not blow cold air and my compressor clutch kicks in and off constantly.

TylerSteez

iTrader: (3)

there's a coolant temp SENSOR on the front of the intake manifold which sends coolant temp info to the ECM. Then theres a coolant temp SENDER in the passenger side head that is used for fan control

duanejangula

Thanks for the quick reply. Have somewhat seen that same answer here/there. And to further add to this, it appears to me that the CTS on the intake manifold tells the dash board temp gauge its reading. If i am not correct please correct me!!!!!

Now to my next question:
The CTS on the passenger side head is used for electric fan control. My 5.7L engine has two fans which i will refer to as driver side and passenger side...
So does this CTS only control the on/off on the drivers side fan????? This fan works/comes on when my dash board gauge is appr 230 degrees or so (which i have seen in various posts/websites is supposed to do that when engine reaches appr 238 degrees).

My passenger side fan does not come on at all. So is this fan merely controlled by A/C on/off (assuming A/c is running properly), OR are there other factors that control the on/off of the passenger fan??

Have read in places where speed of the car will also turn off both fans since outside air will cause cooling air thru the radiator..
Thanks a bunch for any info...

TylerSteez

iTrader: (3)

whoops forgot about the coolant sending unit on the driver side head, that one is the one that sends the info to the temp gauge on the dash. I believe the secondary fan is solely controlled by the AC, I've only had thirdgens with a single fan so I'm not the guy to answer that, hopefully someone else will chime in for that.

henryd3

iTrader: (128)

As Tyler said, the sender on driver side of the head feeds the temp gauge. The CTS tells the computer what the temps are and the computer uses this info to turn on the driver side fan. Passenger side fan actuated by the fan switch on passenger side between back two plugs. AC on also actuates that secondary fan. You can test the fan and relay by grounding the wire going to the fan switch with key on. That should make the secondary fan go on. The switch is set to actuate the fan after the other fan when the temps get higher. Fan switches fail often and can be replaced with switches that turn on the fan at differing lower temps id desired.
AC probably low on refrigerant and needs recharging.

duanejangula

Howdy again. So in reviewing my prior posts and i took another good look at the engine bay. Dont have a hoist and being its so crowded under the hood, things are very hard to see. So again i have to ask this question.

Appears there are 3 coolant temp sensors (cts).
) One cts is under the throttle body area under the thermostat housing area. Refer to this as #1.
) One cts is on driver side area close to the first plug on the front of engine. Refer to this as #2.
) One cts is on passenger side area close to last plug on the back of engine. Refer to this one as #3.

Does anybody know which cts is responsible for what??? Since we have 2 cooling fans, and a dash gauge i take it that each one of the cts's does something. If anybody knows for sure (not guessing), i would sure appreciate it., I recently bought the car and trying to learn as much as i can about it. Thanks again.

henryd3

iTrader: (128)

I answered all of this in post #5, but let me try again. #1 is the ONLY CTS. That stands for coolant temp sensor. It gives temp info to the computer for various things it controls including the driver side fan. #2 is the temp SENDER that provides the info to make the coolant temp gauge work. #3 is the FAN SWITCH which turns on the passenger side fan when the temp gets high enough( around 238 degrees or so ) by grounding out the wire going to the fan relay. They are three entirely different parts.
Try rereading this whole thread again . All of these questions have been answered a few times ...