why the cooling fan wont start without turning the ac on?

The fans do not always run. Only when the coolant has reached a factory default setting temperature. This is normal. plug that back in right away

I ran the car for a good 35 minutes and wont start when start to rise the temp I turn the a/c and go to normal...

it loos like this

yes I changed that

the fan only start with the a/c on or if disconnect the sensor which I put back on

OK how hot is your definition of 'hot'...way up in red or just above normal?

when I see it gets close to red I turn on the a/c....

The A/C thing is to blow air through the evaporator. So it will always come on regardless of how cold it is, that IS normal. Hmmm, this is a good one let me look at some stuff

LOL I KNOW BUT THAT WHY I TURN IT ON THAT WAY WONT GET TO RED

Allright, I don't mean to insult you I am trying to help here

Now I'm thinking thermostat

no I didn't take it as it...just that I don't want to blow the head...you are doing too much by helping thank

oh ok ill change it and get back to you...

Please do i'd like to know

putoli hold on forget thermostat for minute, you want cooling fan right,ok maby you have 2 fans one for air cond and one for engine look in grille see, air one works ok maby another is smoked [broke] or look for fan reley under hood and all fuses, worst case is hot wire it at inlet wire fan motor from a key turned on hot spot and let run always,,, that works as bypass ,dont laugh doctors do this kind of s--- all the time

come on, jimmy, making it run ALL the time is not the solution, they don't run at highway speeds anyway, 45mph creates enough airflow the fan is redundant and will burn out much sooner than it would have. I can tell you are an intelligent guy that knows cars, I'm surprised you suggested that

no joke the car is 16 years old , and he obviously needs the car daily and it will blow the thin heads between the valves if to hot,like i say" in worst case "even temporally , something small as it may sound, can compound to disaster, without a band aid ,till discovery ,and at one time i did just that back in the day when chevy cavilier and most other cars except the imports at the time had same 77 cent units, yes in production 77 cents cost ,,wow,, and they lasted amazingly years, and an aftermarket unit was about 36 dollars if needed, am i off the hook thinking like this? , was always as ! seriously

jimmy the problem is that both fan are working when the a/c is on just got the the garage and will check the fuse panel and will try the thermostat...another thing is that the hose coming out of the thermostat housing is cold even when the temp rises above normal

That hose coming out is the return of hot to the radiator, it flows in that direction and should be hot. Change that thermostat regardless of fan issues, and use maybe a 160 degree. That coolant is not coming out as it should, trapped in engine

ok working on that....160 degree? thanks guys

I would. That means it will open sooner, at a lower temperature, but will still keep it at proper operating temperature. Actually, go 175. Thinking about it, 160 is a bit to cold to open.

cool david changed the thermostat and the temp sensor and is working perfect....thanks guys

thank you very much....

I have a 99 nissan altima and my fans are only staying on for like 10sec. And then they go off and is making my car overheat. I just put a new radiator new temperature sensor.

And also new thermostat

Can you help

bro i have the same problem, i think you have a short or your 31 radiator relay is bad also check that that temperature sensor.

#1 relay sorry

Question: I have a 2003 nissan maxima that makes a funny humming sound. I had a accident when someone back up into me, my hood wont close and now this sound. I was told i need to have both cooling fans working at all times. Only the AC cooling fan was seen on. What can i do or better yet what do i need to do and any idea on how much im looking at

Would this also happen to my 1999 alero oldsmobile

I have a 1997 Prelude. Fans do not start until a/c is turned on. Checked relay and if fan has power. Could it be the thermostat?

I have a 91 chevy lumina and both radiator fans will not work unless you hook them up directly to the battery.I hooked it up one time and the air conditioner clutch kicked on and stayed running one time but now it will not run at all.The reason I hooked the fans up direct is because the temperature gauge went all the way up to the max and the fans would not turn on.Can you help me.I have already checked every fuse in the car.I was getting cold air out of the air conditioner but now I am not.Could it be the three relay fuses might have went out on them.

How can I fix my problem

Either 1 of 2 problems. The engine coolant temperature sensor or the switch that kicks on the fans is bad. Some switches are mounted on the engine and some on the bottom ...etc.. of the radiator. The ECT sensor you can usually find near the thermostat where it leads into one of the hoses leading from your radiator to your engine. Check your relays to see if they are working. Usually if you take it off and try putting it back in ...it clicks or turns your fan on (assuming you are checking fan no. 1 for example). Is this helping anyone so far??

Pls i need help my nissan altima 3.5se the fan off but when i turn on the ac its running...pls

Hello guys I have a 2004 Nissan Maxima.. Love the car...recently the car would not start. After further investigation I needed a starter...no these engines where the positive connection is its like a heavy wire that connects everything starter, I believe like alot of ecm connectors also...it's a fuse.... It was arching bad......thankfully dispute that it didn't blow....before I took starter out, I had zero codes....but after bypassing that connection wire...it's throwing couple codes at me..... It would not work right hooking it up back the normal way for some reason.... can it be that I'm getting these codes cuz of my bypass operation? Help! Stumped in New York....

Need help guys. My nissan sentra 2000 ac and blower fan dont work when the car is parked under the sun for a while. Encountered it several times. Ac and blower work again after it is parked in a cooler place. Thanks.

Hey guys my 2003 nissan sentra gxe is not cooling this is what i have experienced : when driving the car doesnt over heat (airflow from driving) but when i sit in one spot for a long time it will start to heat up. Just tried turning on the ac to see if it gets a fan to start. It does start the ac fan when i turn on the ac but the other fan has no movement

Check your fuse, relay, and thermo switch. run a positive and neg from the battery to the dead fan to see if the fan works, if the fan doesnt spin ( dead). If the fan works, find you temp sensor and bridge the connect ( this acts as if the switch is close position and sending signal to the fan to turn on ) if the fan works - change the switct.

Altima 2008 both fans only run when Ac turned on, but both fans stop when Ac turns off nd car heats up. What is the problem?

I have a 2000 nissan altima. I replaced the fan and temperature control switch and replaced the relay and fuses and nothing worked but as soon as i unplugged the temperature control then the fans kicked on