Radiator fan relay

[Okidokee]

Hi,

I own a RHD Honda Civic 1.4L (EC9). The electric fan is not coming on. The coolant reservoir overflowed last time out. The radiator cap is 1-year-old and functional. The fan works when connected directly to the battery. The temperature sender on the block appears to be good. The upper radiator hose becomes hot but the lower hose does not. There are no gas bubbles appearing in the radiator coolant on throttle and there appears to be no oil in the coolant or coolant in the oil, so I don't think blown head gasket. The fan switch does not read 12V when normal operating temperature is reached. The fan fuse is good. I am thinking defective fan relay but I have not been able to locate it. Is anyone able to tell me where it is on this model?

I am also concerned by the complete absence of heat in the lower radiator hose and wonder if the thermostat may be stuck closed.

If anyone can tell me where the relay is located and/or offer an opinion on the coolant overflow and thermostat issues, I'd be most grateful.

 

[Mr.Baker]

Had to do some reading and researching, because I could not recall off the top of my head, but this is what I found...
The cooling fan relay is located on the passenger side inner fender panel behind the battery.

 

[Okidokee]

Very kind of you to go to that trouble but there is no relay in that location. I spoke to a Honda parts dealer yesterday that told me there is no fan relay no my model, just a thermal switch hidden behind the block above the oil filter and a thermal sensor between the thermostat and the distributor. I find this strange but will test the thermal switch now that I know there is one. The dealer told me that the thermal switch is a common point of failure on 4th generation Civics.

 

[Mr.Baker]

Correct, there is a fan switch in that location, but also a relay...

 

[Okidokee]

The cooling fan relay is located on the passenger side inner fender panel behind the battery.

Thanks for your reply. The problem was a faulty temperature sending unit, which screws into the rear of the block beneath the carburetor - almost impossible to see without a mirror and even then.... Easiest way is just to feel for it. Apparently, this part commonly fails on older civics.