Check your radiator/condenser fan operation NOW

kurtisk

Active member
Joined
Nov 17, 2002
Location
Tampa, Florida
TDI
2015 Passat SEL TDI, red on black, Stock; 2000 New Beetle TDI Auto swapped for 5spd, Cybergreen on Black, PSI Power Box; 2015 Golf Sportwagen SE TDI, red on tan; 2014 Beetle Convertible TDI Premium Edition, pearl white on black leather
I see references to the ambient temp sensor. I have a 2000 beetle and notice my outside temp gauge by the clock does not read accurately (sometimes in it reads -22 and I live in FL). Is this displaying the output from the same ambient temp sensor used by the AC and ECU, the one located by the driver's side fog light behind the grill?
 

lovemybug

Veteran Member
Joined
Mar 11, 2007
Location
SE Wisconsin
TDI
2002 Red Beetle
I see references to the ambient temp sensor. I have a 2000 beetle and notice my outside temp gauge by the clock does not read accurately (sometimes in it reads -22 and I live in FL). Is this displaying the output from the same ambient temp sensor used by the AC and ECU, the one located by the driver's side fog light behind the grill?
Yes, it is that sensor that it displays. Before you replace the sensor, check the wiring going to the connector. You may have a damaged wire that needs to be fixed.
 

artc

Member
Joined
Aug 25, 2017
Location
bradenton fl
TDI
2005 passat 20
2005 passat gls tdi replaced passenger fan also ac compressor control relay still passenger fan wont run.Driver side fan belt is not electric pulley driven. HELP!
 

artc

Member
Joined
Aug 25, 2017
Location
bradenton fl
TDI
2005 passat 20
Fan problem

On my 05 passat tdi replaced passenger side fan also new ac compressor control relay fan wont turn at all driver side fan not electric its pulley driven HELP please.
 
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ToxicDoc

Veteran Member
Joined
Mar 1, 2018
Location
Virginia, US
TDI
2001 Jetta, S7, .216
for 4 years I've had intermittent AC operation. Finally found corroded terminals at the temp switch for the radiator. something worth looking at.
 

artc

Member
Joined
Aug 25, 2017
Location
bradenton fl
TDI
2005 passat 20
air works until i come to a stop but fan in front of engine does not turn passenger side engine new fan new ac compressor control relay also help
 

yvon g

Veteran Member
Joined
Sep 12, 2002
Location
Salisbury New Brunswick Canada
TDI
2014 jetta trendline 2.0 liter
i just bought a 2014 jetta gas job, 2.0 liter. is the check for fans the same? turned key on, fan on low, a/c on.....fans don't come on....problem or different way to check a/c fan operation?
 

AnotherPerson

Veteran Member
Joined
Oct 24, 2015
Location
New Orleans
TDI
1999 Beetle
Just a small update. Found out both of my low speed fans (VDO) are shot again. Going to mess with them some tomorrow, been hearing a weird electrical sound so I guess it was one of the fans going.
 

AnotherPerson

Veteran Member
Joined
Oct 24, 2015
Location
New Orleans
TDI
1999 Beetle
Just a small update. Found out both of my low speed fans (VDO) are shot again. Going to mess with them some tomorrow, been hearing a weird electrical sound so I guess it was one of the fans going.


Turned out to be the fcm. In vw fashion my car has something strange that nobody else has so I’m stuck with a Chinese replacement. Too bad I can’t change the connector for this one.


Sent from my iPhone using Tapatalk
 

Rinderle_77

Member
Joined
May 29, 2018
Location
GJ, CO
TDI
2000 Beetle TDI, 2015 Audi Q7 3.0TDI
Thanks to this thread being a Sticky, I discovered that the fans were both fried, before cooking the AC system, on the bargain beetle I just recently purchased. Saved me a pile of headaches! Replaced the fan assembly this afternoon (with a Chinese Ebay setup for $80). I guess I got what I paid for, as the RH condenser fan made it about 10 min before there was smoke coming out the hub....like the shaft is spinning inside the fan hub and melting the plastic. Yes, they both spun freely after install, and worked as they should in the test. Ebay seller is sending out a new (free replacement) set tomorrow, so hopefully it was just a freak happening.
 

AnotherPerson

Veteran Member
Joined
Oct 24, 2015
Location
New Orleans
TDI
1999 Beetle
Thanks to this thread being a Sticky, I discovered that the fans were both fried, before cooking the AC system, on the bargain beetle I just recently purchased. Saved me a pile of headaches! Replaced the fan assembly this afternoon (with a Chinese Ebay setup for $80). I guess I got what I paid for, as the RH condenser fan made it about 10 min before there was smoke coming out the hub....like the shaft is spinning inside the fan hub and melting the plastic. Yes, they both spun freely after install, and worked as they should in the test. Ebay seller is sending out a new (free replacement) set tomorrow, so hopefully it was just a freak happening.

It’s not the fan that dies. The low speed resistor in the fan is too small. Vw designed it wrong and nobody ever put a larger resistor to handle it.
 

tschager

Member
Joined
Jan 6, 2010
Location
Landrum, SC
TDI
2002 Jetta Wagon
Success

Well, once again the TDI Club and this blog saved the day. I drove the wagon this morning and the AC worked fine. Got in it this afternoon to take a drive and no AC. The blower fan worked fine but not cooling. I looked at the beginning of this very long thread and there was a troubleshooting step where you try to see if the cooling fans come on when the key's turned on while the motor's hot and to see if the other fan comes on if the AC button is pressed.



I did this and nothing, no fan, nothing. So, fuse 16 was the first check. Not bad. Next, the green fuses on top of the battery. The far left of the 3 fuses didn't want to come out of the holder so I got the pliers and it came out. Contact was black and there looked to be a little bit of melting on the fuse holder. Hmmm.



The fuse got cleaned and swapped with one of the others. The key was then turned on and guess what, the fans started working. Good sign. Now I started the engine and engaged the AC. Click and cooling started happening. Looks like my 16 year old electrical system may be starting to show a little corrosion and resistance. Good news is that all of the fuses are now cleaned and the AC system works - along with whatever circuits run from the other 2 fuses.



Thanks again, Guys!!!
 

SilverGhost

Veteran Member
Joined
Mar 25, 2005
Location
Back in So Flo - St Lucie
TDI
'05 Golf - totaled :(, wife's '13 Beetle - buy back, TDIless
Unless you want to service the fuse as often as you fuel the car, I would put replacing the fuse panel on your list of things to do.

Jason
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
I had stuck on fans year ago. Much melted plastic and carnage in the fuse holder. Cleaned it all up, never happened again.
Still and all, replacing the fuse panel is good advice.
 

Mapachurro

Well-known member
Joined
Jun 30, 2016
Location
Cleveland, OH
TDI
2004 BEW Golf GLS
Hey guys. This thread is epic, and here is my contribution.

I've got a 2004 BEW Golf. I bought it last November, and now that it's summer, it does not blow cold. This is what I've done so far:

-Fan check. Passenger's side works, driver's is out.
-Checked fuses in door panel, and all fuses on top of the battery. No corrosion, melting, or blackening, and I think I might have replaced the whole battery fuse tray over the winter, so internal melting of the tray is unlikely.

I took a video of what the compressor clutch does while running, because it seems weird: it runs... slow.

https://youtu.be/NyfhOtQ2BUs

Am I looking at a bad clutch, here? Or do I first need to get both fans working and see what happens?

You may be able to hear me in the background saying when I'm turning the fan on and the A/C, but it makes no difference -- same behavior the whole way through. Also pardon the HID ballast in the foreground of the video :-D

Thanks in advance--love this community.

Sent from my SM-N920V using Tapatalk
 

SilverGhost

Veteran Member
Joined
Mar 25, 2005
Location
Back in So Flo - St Lucie
TDI
'05 Golf - totaled :(, wife's '13 Beetle - buy back, TDIless
@Mapachurro - is the nut in the middle turning? Looks like the clutch is not engaged and the compressor is just free wheeling. BTW - not a good sign if the compressor turns that easily - it maybe a broken clutch or the shaft connecting clutch to the inside. Or even the splines on the shaft are stripped.

I would shut the engine off, make sure its not too hot, try to turn the middle part.

Jason
 

Mapachurro

Well-known member
Joined
Jun 30, 2016
Location
Cleveland, OH
TDI
2004 BEW Golf GLS
Hey Jason,

Confirmed, I can easily turn the inside part of the pulley with the engine off. You're saying that indicates that a significant mechanical portion of the pulley system is broken/nonfunctional, right?

Thanks

Oliver

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SilverGhost

Veteran Member
Joined
Mar 25, 2005
Location
Back in So Flo - St Lucie
TDI
'05 Golf - totaled :(, wife's '13 Beetle - buy back, TDIless
I would hope it's just a pulley, but may actually be the compressor.

Usually the mechanical friction of the compressor means it is very hard to turn by hand. if you can just spin it easily then my guess is the shaft is broken and you need a new compressor.

Jason
 

Mapachurro

Well-known member
Joined
Jun 30, 2016
Location
Cleveland, OH
TDI
2004 BEW Golf GLS
Hey guys,

I spent some time underneath the car, just checking that, you know, all the electrical connections were OK, and they definitely weren't! PO's mechanic had at some point installed the alternator-to-battery cable badly--they put it on the engine side of the oil filter, instead of the radiator side, which took away just enough give in the cable that the plug near the battery tray couldn't connect. (Not to mention exposing it to additional heat...)

Then, underneath on the driver's side, the triangle-shaped plug (the one that carries the fan signal...? I remember seeing it in the fan repair writeup) was hanging loose.

Once I got those two plugged in, we had full A/C functionality.

Now it's just a question of repairing/replacing the driver's side fan.

Cheers!


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jaysonl76

Member
Joined
Aug 23, 2016
Location
San Diego, CA
TDI
2005 Golf
So found my driver side burned up. Ordered a replacement that will be here in a few days. What harm can I cause if I keep driving? Driving temp has been fine so far? Thanks
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
The A/C system will be materially stressed without the low speed fan working, especially in hot temperatures; the risk is coking of the compressor oil which, if it occurs, will start a destructive cycle that can lead to its failure.

There's little risk if you don't use the A/C, but I assume you want to this time of the year in your area..... if you do use it there's somewhat-more risk, rising quite materially if you drive in stop and go or city traffic.
 

seansco

New member
Joined
Jul 24, 2018
Location
Iowa
TDI
2002 Jetta TDI
NO AC / No Fans / No compressor / Fuses OK

Just "inherited" (bought for $500 at my father-in-laws estate auction) a 2002 Jetta TDI. He called it his "little limo". Car runs and rides good but no AC.

What I have checked so far:
fan check: key on, motor not running, ac and ac blower on. -- neither radiator fan is running.
compressor check: car on, ac on full blast. -- neither radiator fan is running. compressor NOT running.


I have checked the fuses on the battery and cabin fuse box and they look good. I've checked the pdf at the beginning of this thread and I am a little confused on where to go next. Any direction would be great.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
The first step is to find someone with a set of gauges and see if there's pressure in the system. If not neither the fans or compressor will come on.

If there IS pressure (more than ~35psi) then it's odds-on either the sensor is bad, the wiring is bad, the FCM is bad or some combination of the above; the guide at the front of this thread is appropriate.

If not then you have some work ahead of you as you need to both find and fix the leak and, given that it sat for a while, need *at least* a dryer replacement (and maybe much more); the electrical element in this thread is not in-play.
 

crashtested

Veteran Member
Joined
Jun 15, 2010
Location
Nelson, BC
TDI
2014 GSW Trendline 6MT, 2004 Jetta GLS 5MT (sold), 2010 GSW Highline 6MT (buy back)
The A/C system will be materially stressed without the low speed fan working, especially in hot temperatures; the risk is coking of the compressor oil which, if it occurs, will start a destructive cycle that can lead to its failure.

Why? It won't be working any harder then if the main cooling fan were running.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
Why? It won't be working any harder then if the main cooling fan were running.
Absolutely NOT true.

If the condenser does not have adequate airflow through it then the entire system runs hotter. Remember that when compressing gas it gets hot (same amount of heat in the molecules in a smaller space = hotter temperature.) If the condenser is unable to release that heat into the atmosphere because there is no airflow through it then the gas will pick up more heat in the evaporator and when compressed it will get even hotter. In response you'll turn the fan up higher and the temperature dial down lower, which will in turn pick up more heat from the cabin to be removed -- that can't be removed.

If the oil in the system reaches the breakdown temperature then it cokes. If you've ever seen the inside of a system where it's happened there's black material all over the inside, especially in the compressor. That used to be oil and not only does it plug things up it doesn't lubricate very well either.
 

dremd

Veteran Member
Joined
May 31, 2007
Location
South Louisiana
TDI
06 sprinter. 03 jetta wagon premium with 6 speed ALH swap, 14 JSW
Why? It won't be working any harder then if the main cooling fan were running.

Completely false.

Higher temperatures cause high side pressure to spike, ideally the fan control module detects the high pressure and shuts off the compressor, but with one fan it will probably just make the compressor work 2x as hard.
 
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