99 dodge caravan 3.3 no radiator cooling fan

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  #1  
Old 05-17-11, 07:48 PM
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99 dodge caravan 3.3 no radiator cooling fan

Kinda long, but please bear with me:
Sunday night driving in stop & go construction zone traffic our 99 Caravan overheated as my wife was driving & (I was following in another car).
She pulled over & so did I. A small amount of coolent was on the ground. The temp was in the red, but the radiator fans weren't running.

99 dodge Grand Caravan 3.3 2wd w/AC.

After cooling off, I added about 1 inch of water to the radiator & drove home. (I ran the heater the whole 100 miles).
Next day I started to trouble shoot.

I ran the motor & turned on the AC to heat it up faster. The radiator fans never turned on, & after a while the AC compressor locked up & the serpentine belt was smoking. (rats!)

Radiator fans first:
One fan spun freely by hand, but the other was hard to spin. I applied 12 volts to the hard to spin one & it ran but was "rachetty"
I applied 12 volts to the freely spinning fan terminals, & the fan did not move, but the jumper wires I was using got red hot & the pin of the fan melted the plastic.
fine, easy fix I thought.
I installed a new fan unit. I ran the motor & let the temp go up to above the centerpoint (where the fans usually kick in), but they still did not turn on.

Fine, (I think), I've been here before. Maybe it's the infamous Dodge radiator cooling fan relay. (the 4 pin one on the frame next to the radiator drain plug)
I had replaced that relay about 5 years ago. (they are known as a common problem)
So I bought a new one of those, installed it, and ... you guessed it... the fan motors still won't come on.

The temp gauge on the dash seems to be working fine (goes up gradually & goes down when off), so I am guessing the temp sending unit next to the thermostat housing is working, right?

I don't see any obviously burned wiring. There is a burned smell, but I'm thinking that is the serpentine belt that smoked.

Does anyone have any ideas of something else to look for?
Thanks for any ideas.
 
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  #2  
Old 05-18-11, 04:44 AM
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I would check a wiring diagram to see how the circuit runs; I'm not certain the temp sesnor you mentioned is the one that controls the fans. I'm guessing you have a problem with the temp sensor talking to the computer, but wouldn't hurt to meter all the wires in the circuit for an open.

The ac compressor locked up after a while????? That is not a good sign.
 
  #3  
Old 05-18-11, 12:34 PM
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man, did you have to go that high on temp that ur a/c compressor locked up on you? well, no worries, been there before. remove compressor and pour some oil into it and hand crank it. it will slowly loosen up.

but anyhow. you did not mention temperature sensor. you mentioned this:

[I]Maybe it's the infamous Dodge radiator cooling fan relay.[/I]

i am not sure why you are not even looking at temp sensor, and you possibly have 2 of those, as some cars now have one for thermostat housing and one for engine block.
instead of jumping the fans, maybe you should have checked if there's any power coming to them?
did you consider reading DTC codes? it also might be a good starting point.
 
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Old 05-20-11, 01:01 PM
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i am not sure why you are not even looking at temp sensor, and you possibly have 2 of those, as some cars now have one for thermostat housing and one for engine block.
instead of jumping the fans, maybe you should have checked if there's any power coming to them?
did you consider reading DTC codes? it also might be a good starting point.
Well, probably I'm not the sharpest tool in the shed... I just try to learn as I go.

Ok, here is my next installment in this story:
I gave up. I was at our car shop picking up my wife's car (needed fender repair) & i made an appointment for their guy to take a look at my car next week.
On the way home, about 10 miles, I ran the air conditioner. The car's temp gauge stayed at the half way mark.
I've had this car for about 6 years, and always the radiator fans would turn on at "just under" the half way mark.
When I got home, I just let the car run. I watched the level in the coolant reservoir rise & the temp gauge needle climb... to just above the halfway mark.
Then the Radiator fans turned on././
I let it sit there for 10 minutes and with the AC running, the fans cycled off & on several times, but at a little higher temperature than I have been used to.

Could it be, that the "logic" of the newly installed relay, is just cutting in & turning on the fans at a little higher temp than the previous one?
 
  #5  
Old 05-20-11, 03:33 PM
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disregard.

hey, glad it works!!
 
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