About Van Expertise I have been maintaining a fleet of approximately 55 light, medium and heavy vehicles for over 20 years. Most are 4X4 pickups and off road fire fighting trucks. Some medium duty trucks. Some military light trucks.
I can answer most questions concerning 4X4 engine, drive line, suspension, electrical, and fuel, both diesel and gasoline. Ford, GM, and Dodge, old and new, but prefferably not newer than 99.
Expert: Van Date: 8/5/2007 Subject: engine coolant fan
Question 96 Olds Cutlass Supreme 3100 engine. I was idling with A/C off and notice the engine temp climbing. I opened the hood and neither fan was running. What I did was turn the A/C on and one fan was running then and gradually cooled down. When I start the car cold, I have seen both fans come on, so I know its not the fans themselves. I have ruled out the controllers(relays) by unplugging them each while the fan is running and the fan starts and stops with plugging in and unplugging relay from box. I think it may be the temp switch not turning the fan on with high temp. I found the temp sensor near the thermostat under the throttle body) with three wires. Is this the correct one to replace? I would think that the radiator temp would be measured for this purpose, but the only sensor on the radiator that I can see is near the trans cooler and I would think that it is for that purpose.I do have an engine temp gauge in the dash.
Answer Hi Phil,
I believe that sensor in the radiator is a coolant level sensor.
The one near the thermostat should be the one that sends the signal to the ECM, which operates the relay.
Here is a link that tells how the sensor should read.
