I gotta 2000 Acoord LX 4-cyl. automatic. Bout a month or so ago both the fans went out. Replaced both of em. Then they still wouldn't run. Jumped the temperature sensor on thermostat housing, fans kicked on. Replaced that one. Then they still didn't kick on. found ECT sensor. jumped that one, fans kicked on. Somewhere along the lines the starter went out. Replaced starter... fans still wont kick on... I have replaced the thermostat twice. I have checked fuses, relays, and whatever else I could. I am at wits end... someone please help!!!!

 

Hi,

Give me a minute or two to put some things together.

 

Hello,

1. With the engine running, turn on the A/C, does both cooling fans run?

2. Generally, you would not jump the ECT sensor connector to test the cooling fans. There might be a risk of possibly damaging something.

The ECT sensor is used to send voltage signals to the ECM/PCM to determine the amount of injected fuel and various other engine functions. The ECT sensor is a thermistor, or in other words it is a thermal resistor. The resistance decreases as coolant temperature increases. The lower the resistance, the higher voltage is allowed through to the ECM/PCM. So, essentially, when you jumped the harness connector to the ECT, there was practically no resistance; so, the ECM/PCM saw it as high coolant temperature.

3. On the thermostat housing, that was the radiator fan switch. It is a normally open type of switch. When the coolant temperature is above 199 degrees F, that switch supposed to close and turn on both cooling fans. Jumping fan switch harness connector to check the fan operation was okay.

Currently (right now ), when you jump the radiator fan switch connector and turn the car on, does both fans run?

Do you know the part number for the radiator fan switch you used?

4. You said fuses were checked. No. 57(20A) and 58(20A) in under-hood fuse/relay box, and No. 3(7.5A) in driver's side dash fuse/relay box?