car will overheat at idle with the air/ac on... can't get the radiator fan to turn on... jumped the fan motor yesterday and the fan does work, what else to check? wouldn't the engine coolant temperature sensor throw a code?

 

The fan motor is controlled by a relay, most likely attached to the front wall or somewhere around the radiator bracing. Follow the wires. . .

 

also, check your thermostat. If your thermostat isn't opening, your relay might not be activating, hence the overheating.

Take your thermostat and slow put it to boil in a pot of water. If it opens, check the relay. If not, then get a new thermostat.

 

The coolant temp sensor is seperate from the fan temp switch. The coolant temp sensor is a sensor (variable resistance/voltage with temperature) and the fan switch is an on/off temp controlled switch. It's more common for the temp switch to go bad than the fan relay.

 

thats the sensor usually near the thermostat right? I remember on my b18a1 it was right next to it.

 

fan sensor on honda is on the thermostat housing.....two wire plug on the bubble part of the thermostat housing........easy way to check is to pull plug off....with the key on jump the connector (the plug) fan should turn on....if not check fuses and thermostat itself like crxfn said a new one isn't that much either

 

thanks guys.... will get on it today