coolant Temp Sensor Working

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HighCard77

NAXJA Forum User

Location

North Bay Canada

• Apr 22, 2009

• #1

My 99 sport Aux Fan comes on for 2 secs and shuts off and cycles like this no matter if the motor is hot or cold. My relay finally broke and I just replaced it. Shouldn't the aux fan only come on when the motor is hot ??

 

B

bfred

NAXJA Forum User

Location

illinois

• Apr 22, 2009

• #2

Check to be sure a/c compressor isnt cycling on & off at the same time. Sounds like what it does when your low on freon. Compressor will run in the a/c & defrost positions. As far as I know, this is the only reason aux fan should be on with engine cold (runs entire time w/ comp.)

 

H

HighCard77

NAXJA Forum User

Location

North Bay Canada

• Apr 22, 2009

• #3

Yes the A/C is cycling at the same time. So is my Coolant sensor working properly ?

 

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winterbeater

NAXJA Forum User

Location

Royal Oak, Michigan

• Apr 22, 2009

• #4

The later years (very possibly including 99) should only turn on aux pan when hot. What does your temp gage say? Does it also do this when the AC and defrost are off?

 

H

HighCard77

NAXJA Forum User

Location

North Bay Canada

• Apr 22, 2009

• #5

the fan cycles continously at cold and operating temps. My Temp gauge on the dash works fine. I just looked closely at the coolant sensor...the black electical connector of the sensor turns inside the threaded brass base. I think that might be the problem.