I have a 1990 camero rs, 305, vin e. My fan will not kick on (single fan), the fan relay is good (swapped with fuel pump relay), fan will work with ac on. Checked fuse at fuse pannel and it is good, also has power to fuse at panel. Checked fusible link near battery and it was good. Replaced coolant sensor also. Replaced 195 deg thermostat with 180deg. How do you jump collant temp sensor, to test if the fan will kick on? Do you disconnect terminal and take a wire and loop at connector? Also, if the fan kicks on when I ground the temp sensor connector, does that mean that the new temp sensor is bad? If the fan does not kick on when I ground the connector, then is there a short or another fuseible link bad, and where is the link located. I also ran a test lite to temp sensor connector and it does show power to sensor. Also checked power to relay and it reads hot to relay. Please HELP!!

 

Need help!

 

Make sure you are on the correct cts. there is two. i believe the one you want is on the drivers side of the head by the exhaust manifold. Just saying i made the same mistake once.

 

The temp sensor on the drivers side of the block is only for the temp gage.

 

actually the CTS is up on the intake and can be confused with the gauge temp sensor. the ECM reads what the CTS is seeing and then makes A/F adjustmens.
sounds like your fan switch which is on the pass side next to the dip stick in the head. make sure your wire isnt broken or un plugged.

word of caution, dont mix up the knock sensor plug with the fan switch plug. they are the same style plug but diff color wires. you will need to drain some of the coolant to remove the fan switch. take this oppertunity to put in a switch that comes on at a lower temp. hypertech offers 2. on @200 off @ 185 and on @ 176 off @166.

 

sorry i didn't clarify. the fan switch is in the head i thought. cts in intake. go through a napa sensor book and u can get a lower temp fan switch for alot less than hypertech. they list on and off temps.

 

To answer you question, if you ground the wire and the fan kicks on then your temp switch in the head is bad.

I put a toggle switch in my dash and tied one side to the wier going to the TS and tied the other end to ground and I can turn on my fans any time I want to.

 

Mike, before you jump to conclusions and start replacing parts, you need to get the engine hot enough for the coolant switch to turn on the fan.
The temperature required for that isn't exactly low, it's almost 240°F. So if your dash gauge reads correctly, you will see it go almost into the red zone when the fan kicks in.
Test it out and let us know what you find. Because these temp switches don't go bad very often but people just don't know what temperature they are rated at.

If you decide, in the end, to swap the temp switch for one rated lower, I would suggest nothing below 225°, I'd say above 230°. But then again, we're back at the original temperature.

Hope this helps.
Lou

 

wire it into a toggle and dont worry about it anymore