1999 Sunfire: Radiator Fan not turning on

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bonestheripper

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Hi fellas,

Glad i stumbled onto this great forum. I'm in need of some assistance.

My gal recently (Friday 9/3/10) acquired a 1999 Pontiac Sunfire, 2.2L engine. The radiator cooling fan is not turning on at all. The plug behind the fan is connected nice and tight and i swapped the cooling fan relay with the heater blower relay thinking it was the relay but no luck. I did notice that the previous owner unpluged the hoses for the heater core so it is bypassed. I dont want to hook up the fan to direct power at all times. i guess it could be the fan that no longer works... Any thoughts?

thanks again.

Bones
 
try applying power directly to the fan to check it. It also could be the sensor. Does the fan come on with the A/C turned on and the car fully warmed up? Is the car overheating?
 
melsg5 said:
try applying power directly to the fan to check it. It also could be the sensor. Does the fan come on with the A/C turned on and the car fully warmed up? Is the car overheating?
Click to expand...

tried the AC while the car was warmed up and idling... fan never came on. the engine runs fine and when you drive it stays cool as long as you're moving... if i sit at idle for a while, the temp gauge just keeps rising and rising. today on my lunch, i cut the fan wires (blue and black) and i used some jumper wires to apply direct power to the fan from the battery.. the fan did not turn on. i'm pretty sure the motor burned out because the connector that goes to fan was slightly melted and burnt. I'm having the fan replaced today and i'll give it another go. if it still doesnt work, it'll either be the relay and/or the sensor. speaking of, which sensor controls the fan and where is it located? i believe the coolant temp sensor controls the fan and that sensor i know is behind the alternator... am i wrong?

thanks for your help.
 
I just purchased a 1999 sunfire a week and a half ago. love this little car. I also have a fan problem. I have already put power to the fan directly and it turns on. What made me look for this problem was i had my first rush hour blast today and watched my temp gauge rise for the first time. Is there a sensor that needs changing? I have checked the fuses by checking the continuity of them, they are good. So im thinking a sensor or relay somewhere? Any suggestions? if so what are they, and where are they going to be located.... Im no mechanic but i can figure some ezier things out. Thanks for any help!
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1999 Sunfire:
I also am having a problem with my fan not turning on, I put direct power to the fan and it works. So the problem lies with supplying power. I have checked continuity of the fuses, they are good. I am thinking relay or sensor? Im not a mechanic by any means but i can figure out some ezier things with a little instruction. So if you have any tips on where to start other than if the fan works with direct power, or fuses i would appreciate the help.
Thanks, and hope to here from someone!
 
melsg5 said:
try applying power directly to the fan to check it. It also could be the sensor. Does the fan come on with the A/C turned on and the car fully warmed up? Is the car overheating?
Click to expand...

My son told me that his coolant fan is not coming on unless his a/c is on. I have not taken a look yet but i noticed your reply to the post and wondered when you asked if it comes on with the a/c? Is there something that I should look at first?
 
wmnsck said:
1999 Sunfire:
I also am having a problem with my fan not turning on, I put direct power to the fan and it works. So the problem lies with supplying power. I have checked continuity of the fuses, they are good. I am thinking relay or sensor? Im not a mechanic by any means but i can figure out some ezier things with a little instruction. So if you have any tips on where to start other than if the fan works with direct power, or fuses i would appreciate the help.
Thanks, and hope to here from someone!
Click to expand...

The relay is in the fuse/relay box under the hood, on the drivers side. It's marked "cooling fan". The cooling fan and heater relay are the same so try swapping them, then turn on the heater. If the heater comes on then the cooling fan relay is good.

I recently had the same problem, used to almost overheat a lot unless I turned on my heater full blast so the temp didn't rise anymore, and turning on the AC to make the fan go on didn't work either. I had the mechanic look at it and test the connections to the cooling fan motor, and test the relay. Everything worked good, and not really sure if he did anything else but now the fan works.
 
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sunfire cooling fan

Good advise about the relay swapping.

Sometimes the relays will work intermittingly. It's best to change the relay out if it is in question; they cost $7 + change at the parts store.

If the cooling fan is not working, you can bet that the A/C will soon begin to fault as the High pressure switch on the A/C lines will detect the rise in temperature and effect to safety shut down the compressor. When the car is moving it will operate somewhat OK until you stop for a while at a traffic light and the heat builds up.

I had this happen and initially thought it was a slipping drive belt as the belt began to flap and give the scretching sound when the compressor loaded up.

I almost changed the fan motor until the relay finally bought-it and quit all together. I swapped the relay to confirm the problem. Got a new unit and all is well for months now.
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Checked the cooling fan today. I had the car running and the temp guage climbed to the 3rd little line past the 90 c larger line (107.5??) then the rad fan did cut in. When I turn on the a/c the fan cuts in right away at a lower temp. What temp should the rad fan cut in with the a/c off and the car at idle?
 
If it cut in around 107C which is about 225F it's coming in too high. I would start by replacing the sensor.
 
bojanglespa said:
Checked the cooling fan today. I had the car running and the temp guage climbed to the 3rd little line past the 90 c larger line (107.5??) then the rad fan did cut in. When I turn on the a/c the fan cuts in right away at a lower temp. What temp should the rad fan cut in with the a/c off and the car at idle?
Click to expand...

I made a typo...the 107.5 celcius line is a larger line between 90 and 125 celcius. His cuts in at the 3rd smaller line above the 90 celcius line which is below the 107.5 line.
 
So assuming you mean 99C thats 210F which is fine for the fan to start.
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