Anyone know how to troubleshoot if it's the sensor in the block or a bad fan? I swapped relays, so I don't think it's the relay in the fuse panel under the hood. I have a 97 Pontiac Sunfire with the 2.2
You may want to check the engine coolant temp sensor. I mean was the fan working and then it just oneday quit working. Is your guage reading fine in your cluster and just when it hits the red its never turning on. Give us some more detail man so we can further answer your question. My guess would be a bad fan though.
Fuse is also good under the hood. This summer I really noticed it, when I was at an idle the engine would get to just about the red line, I'd have to turn the heat on full blast to keep it from overheating.
On my '93 the coolant fan relay base operating coil
contact 86 is fed from the 25amp A/C fuse
contact 87(the other end of the coil is grounded by the ECM when the Coolant Temp sensor says the temp is 220/223 deg F)****
Contact 30 is fed from a Fusible link on the starter solenoid(Always hot--it's connected to Battery positive.)
When the relay is energised Contact 30 is connected to 87 and on to the Coolant fan
****Grounding Term B of the data link connector will also turn ON the fan.
as will turning on the A/C
If your wiring is the same pulling the coolant fan relay from the base and checking base terminal 30 to ground should give you battery volts(Always hot--it's connected to Battery positive.)if not---
You may have a blown fusible link
If this is good apply 12volts to the fan directly, mine has +12 on B and Ground to A.
I have always felt that the cooling fan comes on too late, I have an overide switch installed to switch the cooling fan on if the temp increases in traffic stops and hot weather.
Hope this helps
Alont
