I read through several posts and could not find this particular issue. 2 1/2 years ago my 94 accord ex 2.2 vtec started overheating at idle. I replaced all sensors, relays, hoses, thermostat, timing belt, water pump, radiator & cap. I notice the radiator fan will only come on when I turn off the ignition. The relay clicks. Shorting out the fan switch does not make the fan come on. Fuses are fine. Car currently has 284k miles, and no other issues. I am absolutely at a loss here, and any ideas are appreciated. Thank you.

 

There is a thermoswitch A on the thermostat housing, below/behind the distributor that enables the fans to run when temp reaches 194F. The engine off thermoswitch B allows one fan (radiaotor?) to run w/ engine off whenever coolant temp reachs 225F.

Find thermoswitch A , remove connector and short the pins w/ small wire. This should cause the fans to come on when keyswitch is turned to On. If not, check fan connectors for 12V to fan. If nothing, check fan drive relays.

good luck

 

I think TexasHonda had a typo:

Find thermoswitch A, remove connector and short the pins w/ small wire. This should cause the fans to come on when keyswitch is turned to On. If not, check fan connectors for 12V to fan. If nothing, check fan drive relays.

Start the engine and turn on the a/c. Do both fans on the radiator turn on?

 

Both thermoswitches are new. I tested switch A near the thermostat housing before posting (sorry if my wording wasn't clear enough) by shorting out the pins and the fan did NOT come on. When I turn on the a/c BOTH fans come on. When I turn the ignition off the passenger side fan turns ON. Swapping out the relays in the fuse box does not affect this outcome, and both relays click when inserted. To be extra sure, I bought a new relay and tried it with the same result.

That leaves the fan drive relays. If both fans work fine- except that one does not work if the engine is running and the a/c turned off- could it still be a fan drive relay? And if so, are these the two black plastic units that attach to the driver's side of the radiator?

Thank you.

 

I misread your first post.

What you are describing is normal. Only the radiator fan will turn on when the car is turned off and the coolant is hot enough to short temperature sensor B.

You may want to run the hose on the a/c condenser and the radiator. Do not use heavy water pressure, because you will bend the fins. You want to clean out any dirt/debris to help air flow.