Have a 95 Civic EX and the radiator fan is not coming on when hot.

1. Tested the fan with direct power and it comes on.
2. Took the connector off the coolant temp sensor next to the t-stat and jumped it, fan does not come on.
3. Swapped relays and still no fan.
4. Ran jumper wire from relay output to ground and now fan comes on when you turn the ignition on.

So has anyone had problems where actually there was a problem with the ECU? Any ideas??

 

temp sensor doesn't turn on the fan, the thermoswitch does. If the thermoswitch goes bad it will cause a non working fan.

is this what you unplugged?

 

Yes, that is what I unplugged and jumped.

 

Bump.. anyone?

 

did you check both relays?

 

What do you mean by both relays, are you referring to the condenser fan relay as the second? By running a ground wire from the radiator fan relay (the one that goes to the ECU & temp sensor) I was able to get the fan to run. So it seems like there is possibly a problem with either the ECU or the wiring going into/out of the ECU?