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Discussion Starter #1
Hi all, I am hoping someone here can help me out.

I have a 2004 VW Jetta 2.0L that is having some issues. When I am driving the temp gauge stays right at 190 as long as I'm moving, but when I come to a stop for a minute the temp will slowly start creeping up. When I start rolling again the temp will come back down to 190 and stay there.

Here's what I think I know. From what I've read here chances are it is not the water pump since the temp is stable while moving. I checked the fuses on the top of the battery and nothing appears to be melted or blown. If I turn the ignition switch on without the motor running and turn on the AC, both fans on the radiator come on.

I've been reading and reading and I think it might be the Fan Control Module or the Relay. Here's when I show my ignorance. Are the Fan Control Module and the Relay two different things? They seem to be used interchangeably on all the forums I read.

Any idea where I should go from here? Any help would be greatly appreciated.
I am definitely not a mechanic but can't really drop the cash to take the car to the dealership right now.

Thanks folks
 

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Discussion Starter #3
To be honest I'm not sure. I live in Ohio there hasn't been much need for AC lately. Would that make a difference? I could try it I guess.
 

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can you scan youre car? a code will lead you in a more specific direction. autozone and advance auto scan for free. just get it scanned, write down the codes, and bring em back here
 

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Discussion Starter #5
There aren't any warning lights on, no check engine light or overheat light. Will I get any codes if I scan it? Again I don't know much, so that's why I'm asking so many questions. Thanks.
 

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Discussion Starter #6
Also, I did drive the car today. Got her warmed up on the highway and turned on the AC. When I came off the highway the temp did come up at a stop, but it did seem to come up a bit slower.
 

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Replace the cheap stuff first. Coolant temp switch, fan switch, thermostat. You could let your car warm up. Open the hood and see if the fan turns on. Then turn on the ac to see if both fans run. That way you know your fans are working.
 

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There aren't any warning lights on, no check engine light or overheat light. Will I get any codes if I scan it? Again I don't know much, so that's why I'm asking so many questions. Thanks.
yes you can still have codes even though there arent any warning lights on.
 

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Well...First off find someone near you that has Vag-Com. I know the "code" readers at all the auto parts stores near me won't read anything other than a O2 code. Other than that I would do like Fubar says and replace both the fan switch and the coolant temp switch. Then see what happens. If that doesn't work then I would get a new thermostat and would also recommend a coolant flush. Keep us posted on any progress/questions
 

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Well...First off find someone near you that has Vag-Com. I know the "code" readers at all the auto parts stores near me won't read anything other than a O2 code. Other than that I would do like Fubar says and replace both the fan switch and the coolant temp switch. Then see what happens. If that doesn't work then I would get a new thermostat and would also recommend a coolant flush. Keep us posted on any progress/questions
do this in that exact order.
 

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park it then idle the car watch your temp gauge and see if your fan is coming on while stopped, if it doesn't its either the fan motor, the relays for it or the temp sensor. to check the fan u can either unplug it and apply a 12v source to it and see if it runs, or u can unplug the temp sensor from their wiring harness and they will usually engage the fan. i usually just apply a 12 volt source to the fan, if it runs its either your relay or sensor. replace the relay they are only cheap if still no get check the sensors. if the thermostat was stuck closed shes overheat while driving not just stoped, if it was stuck open your temp gauge would barely move, ive has every cooling issue know to man on my 2000 golf, its annoying
 

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Discussion Starter #13
Okay, So I'm going to get the coolant sensor and the cooling fan switch.
Just one more question. I've found plenty of videos on how to replace the coolant temp sensor on YouTube, seems pretty straightforward.

I can't find anything on replacing the cooling fan switch though. I think I've located it, about 2/3 of the way up from the bottom of the radiator on the drivers side. Right? Do I need to drain the coolant to replace the switch?

Thanks again for all of your help folks, it is truly appreciated.

I don't think it's the thermostat, I was replaced last year, but who knows.
 

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i replaced that switch that where it is, i dont think u have to drain the coolant it just unscrews and screw in the new one
 
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