Please my 1997 Honda accord radiator fans only work when AC is on. I decided not to use the AC yesterday and the temperature gauge rose up. Please help

rose up to what temperature? Ideally your fans are designed not to switch on until a certain temperature is reached or when you switch on your AC. Normally you won't even be aware when they switch on because most times it's when the car is on motion. Maybe you can be more specific as to what temperature the engine rose to. That will help in telling if there is a problem or not. Please don't rush off to the mechanic yet.

The car actually overheated

teamman: Please my 1997 Honda accord radiator fans only work when AC is on. I decided not to use the AC yesterday and the temperature gauge rose up. Please help

Radiator electric fan has a trigger, apart from A/C compressor switch. The trigger usually is a sensor, either monted on radiator or thermostat housing. Please, dont misplace the temperature sender & CTS as the fan sensor trigger. Though, in some brands or cars, the CTS also serves as the radiator fans trigger. I dont know the electric system of Japs.

Check if all the sensors on thermostat housing or radiator still have their wiring connectors/sockets well plugged in. Start the car, allow it to idle till the needle on the temp guage reaches middle of the guage. If the needle starts to exceed the middle of the guage and the radiator fan doesnt start spinning, then the fan(s) have lost trigger. Either the trigger sensor/switch has failed or the connection is lost somewhere/broken wire/failed relay or blown fuse.

Have you tested to be sure the thermostat still opens? When the temp guage is about to reach the middle, the lower radiator hose should become warm or hot, just like the upper radiator hose. When that happens, it means the thermostat valve has opened to pass hot coolant into radiator, while the water pump flow in cooler coolant into the engine walls from the radiator before the thermostat valve closes up. But if the lower radiator hose still feel cold when the temp guage needle is at the middle, then your thermostat is stuck closed. It will need to be replaced, before it blows off your head gasket.

But if the upper and lower radiator tube/hose feel the same from when the engine is started cold till when it warms, then your thermostat is absent.i.e. your thermostat has been removed, meaning, be ready for engine replacement or engine rebuild soon. Goodluck.


Ikenna.

Hi everyone.

I noticed that my fans keep working even when AC is turned off. Any ideas on what could be the cause

(Please note that Fan works well i.e. Auto ON and OFF, without AC, but as soon as AC is turned on and off, fan keeps working)

DorlanEyes:
Hi everyone.

I noticed that my fans keep working even when AC is turned off. Any ideas on what could be the cause

(Please note that Fan works well i.e. Auto ON and OFF, without AC, but as soon as AC is turned on and off, fan keeps working)

Is this a keke napep

DorlanEyes:
Hi everyone.

I noticed that my fans keep working even when AC is turned off. Any ideas on what could be the cause

(Please note that Fan works well i.e. Auto ON and OFF, without AC, but as soon as AC is turned on and off, fan keeps working)

Perfectly normal, it just means your coolant temp is still higher than set point so your fan will stay running even with engine off till the temperature reaches set point of about 190f 90 c

It wasn't like this before now sir, the fans used to go off as soon as AC is turned off. But in this case the fan keeps working until engine is turned off.

sultaan:



Perfectly normal, it just means your coolant temp is still higher than set point so your fan will stay running even with engine off till the temperature reaches set point of about 190f 90 c

It's a 2003 Toyota Camry sir

honmusa:

Is this a keke napep

It means your fans have lost control from the thermo- switch .

honmusa:
Is this a keke napep

hahahahahaha, not even a single chill. haba!!!!!!!!!

obekediamondfuto:


hahahahahaha, not even a single chill.
haba!!!!!!!!!

it is alyways important for solution seekers state their car model cos every cars comes with their different peculiarities and wiring system or else I will assume it is a keke napep

honmusa:

it is alyways important for solution seekers state their car model cos every cars comes with their different peculiarities and wiring system or else I will assume it is a keke napep

hahahahahaha, it's well boss

Ikenna351:


Radiator electric fan has a trigger, apart from A/C compressor switch. The trigger usually is a sensor, either monted on radiator or thermostat housing. Please, dont misplace the temperature sender & CTS as the fan sensor trigger. Though, in some brands or cars, the CTS also serves as the radiator fans trigger. I dont know the electric system of Japs.

Check if all the sensors on thermostat housing or radiator still have their wiring connectors/sockets well plugged in. Start the car, allow it to idle till the needle on the temp guage reaches middle of the guage. If the needle starts to exceed the middle of the guage and the radiator fan doesnt start spinning, then the fan(s) have lost trigger. Either the trigger sensor/switch has failed or the connection is lost somewhere/broken wire/failed relay or blown fuse.

Have you tested to be sure the thermostat still opens? When the temp guage is about to reach the middle, the lower radiator hose should become warm or hot, just like the upper radiator hose. When that happens, it means the thermostat valve has opened to pass hot coolant into radiator, while the water pump flow in cooler coolant into the engine walls from the radiator before the thermostat valve closes up. But if the lower radiator hose still feel cold when the temp guage needle is at the middle, then your thermostat is stuck closed. It will need to be replaced, before it blows off your head gasket.

But if the upper and lower radiator tube/hose feel the same from when the engine is started cold till when it warms, then your thermostat is absent.i.e. your thermostat has been removed, meaning, be ready for engine replacement or engine rebuild soon. Goodluck.


Ikenna.

U are so 100%

Hy there ! I'm having a serious doubt with my rx300 cooling system : it takes quite long for the radiator fans to kick in and when they do it doesn't take them more than 15 to 20 secs max for them to come off and then it will take at least 5 minutes foe them to come on again , while the engine is running on idle. is this normal ? Shouldn't they run a bit longer ?

Zarkove:
Hy there ! I'm having a serious doubt with my rx300 cooling system : it takes quite long for the radiator fans to kick in and when they do it doesn't take them more than 15 to 20 secs max for them to come off and then it will take at least 5 minutes foe them to come on again , while the engine is running on idle. is this normal ? Shouldn't they run a bit longer ?

Oga ,this is what is being referred to as controlled system ,there is inbuilt controller(ecu ) that will monitor some input signal(engine temperature) and base on that will make the decision on that and will determine the duration the fan will work .

Zarkove:
Hy there ! I'm having a serious doubt with my rx300 cooling system : it takes quite long for the radiator fans to kick in and when they do it doesn't take them more than 15 to 20 secs max for them to come off and then it will take at least 5 minutes foe them to come on again , while the engine is running on idle. is this normal ? Shouldn't they run a bit longer ?

That is exactly how the system is made to run .

If the computer is trying to maintain 90 degrees the fan might come on when it reaches 95 degrees to cool the engine down and it will go off when the engine cools down to 85 degrees to let it warm up

honmusa:


This is what is being referred to as controlled system ,there is inbuilt controller(ecu ) that will monitor some input signal(engine temperature) and base on that will make the decision on that and will determine the duration the fan will work .

Oga good day to you.

This same thing is happenning to my camry 2005. It takes long time for the fan to start and when they do they run for like 15 secs and stop and then start again at a longer time.

When i s/off the engine and i can feel the water boiling when i touch the upper hose with my hand. The lower hose stays hot but not as hot as the upper and not boiling.

This usually happen when i make trips with my neighbourhood. You know,slow movement due to potholes bumps,traffic etc

But all these dont happen when i use the ac either in neighbourhood or express.

Yet In all of these circumstances temp gauge needle remains at the middle.

xavuv:


Oga good day to you.

This same thing is happenning to my camry 2005. It takes long time for the fan to start and when they do they run for like 15 secs and stop and then start again at a longer time.

When i s/off the engine and i can feel the water boiling when i touch the upper hose with my hand. The lower hose stays hot but not as hot as the upper and not boiling.

This usually happen when i make trips with my neighbourhood. You know,slow movement due to potholes bumps,traffic etc

But all these dont happen when i use the ac either in neighbourhood or express.

Yet In all of these circumstances temp gauge needle remains at the middle.

Your cooling system is working 100% perfect.
When you are tired of the ride, you dash me o

xavuv:


Oga good day to you.

This same thing is happenning to my camry 2005. It takes long time for the fan to start and when they do they run for like 15 secs and stop and then start again at a longer time.

When i s/off the engine and i can feel the water boiling when i touch the upper hose with my hand. The lower hose stays hot but not as hot as the upper and not boiling.

This usually happen when i make trips with my neighbourhood. You know,slow movement due to potholes bumps,traffic etc

But all these dont happen when i use the ac either in neighbourhood or express.

Yet In all of these circumstances temp gauge needle remains at the middle.

Here is Another symptom as to what is happening coupled with the one i wrote up � there

In the morning, at idle, when the temp needle reaches middle, i noticed the lower hose is cold while the upper hose is hot,infact collant will flow into the reservoir. But the radiator (upper part) is cold when touched.

But radiator gets hot and lower hose gets warm once i rev the engine or drive out.

Radiaor is not blocked(relatively new), air in the system is not likely, im guessing thermostat or water pump, or even serpeentine belt or maybe some sensors.

Car drives fine,no overheating, ac chills great too
Please help me diagnose.

CC: Sultan,honmussa,gazzuz,urose93,ikenna351,radauto,timifakay,ricki and all other gurus

xavuv:


Here is Another symptom as to what is happening coupled with the one i wrote up � there

In the morning, at idle, when the temp needle reaches middle, i noticed the lower hose is cold while the upper hose is hot,infact collant will flow into the reservoir. But the radiator (upper part) is cold when touched.

But radiator gets hot and lower hose gets warm once i rev the engine or drive out.

Radiaor is not blocked(relatively new), air in the system is not likely, im guessing thermostat or water pump, or even serpeentine belt or maybe some sensors.

Car drives fine,no overheating, ac chills great too
Please help me diagnose.

CC: Sultan,honmussa,gazzuz,urose93,ikenna351,radauto,timifakay,ricki and all other gurus

You are supposed to have coolant in there not water replace with coolant and let see how things will change.

The top hose has hot coolant being pumped from the engine by water pump into the radiator, and the radiator has the less hot coolant going back into the engine

Thermostat is trying to keep the engine running at 190-200f water boils at 212f

I read on the other thread that the Camry guy needs some water to make eba,that is why he is touching hoses up and down.lol