Radiator fan will not stop

1988 Cadillac Sedan DeVille. Automatic. Father in laws car, he called me needing a jump. The radiator fans were running even with car off. I replaced the temperature sensor and the fan relay. Fans still run. Does anyone else have any suggestions?

There’s a few more relays to check out in this circuit.

Low speed fan relay. Medium speed fan relay. High speed fan relay. All located on the left side of the engine compartment.

There’s also another coolant fan relay behind the right side of the instrument panel.

And finally, every relay is controlled through the body control computer. So that’s also a possibilty.

Tester

The relay that I replaced was the coolant fan relay behind the right side of the instrument panel. Are the other three relays just behind the battery on the drivers side? I am hoping that it is not the computer…

There’s another coolant temp relay located on the top center of the engine. I thought that was the one you replaced. Let’s hope that’s the culprit.

Forget that. I was thinking coolant temp sensor.

Tester

Is it located near the temperature sensor that is on the thermostat housing? I do not see a “relay” on the top center of the engine.

I went back and checked the circuit again. There’s also a cooling fan control module located behind the right side of the instrument panel next to the relay. That might be the problem.

Tester

Tester, thank you for your help. I found the location of the 3 fan relays for speed control. They are located behind the battery on top of the wheel well. The high speed relay was hanging up. Problem solved