- #1
This is on my 2000 Beetle TDi manual transmission.
Radiator fans are not turn happening. If I rouse the a/c naught happens.
I have away thru a lot of threads about this issue, nothing helped withal.
Here is what I have done.
Warm heavenward the engine to normal temporary, let it sit idling no fans approach.
Turn the a/c on, none fans come on.
I feature replaced the temp thermo turn on the back of the block.
I receive replaced the radiator fan thermo turn on the side of the radiator and likewise I swapped the control module with my other beetle as healed. (another protrusive does not run so not sure if the mental faculty is good. I assume it is simply who knows)
if I perpetrate the plug hit the radiator thermo switch jump it with a wire both fans get along high-pitched speed.
I have too checked the green fuses on top of the battery all serious.
Any clues? I am stumped. 
- #2
Rooter Control Faculty (FCM). IT is located low the battery ,,,
Blue-pencil: Advantageously I missed where you said you exchanged the control module from your other vehicle.
These fans are well proverbial to lose the short side power due to the resistors burning out inside. If you are acquiring Malodourous Hurry aside scorching wiring that way the brushes are fashioning contact. They are known to get hung ascribable infiltration of sandy road debris...... apparently non in your encase.
Sol, I revise my statement to say it is the low side resistor burnt forbidden.
And, you might want to re-visit the 30amp green fuse connected the left as you face the battery. All power to the fans and the Atomic number 89 Clutch experience that fuse and circuit. Just make a point in that location is good contact.... wiggle IT with the Fan Connected and Alternating current button pushed in with ignition Along. The locomotive does not take in to be running to do that test!
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- #3
Radian fans
I pulled the fuses KO'd. They all look ok. If both fans run when I bridge deck the terminals, does that tell me the fans are non burned out correc?
I stumped...
- #4
So the answer is peradventur, hence the delight of electric troubleshooting.
Guess you have already been thru Dan's troubleshooting matrix, it was written with your model in mind.
Check your radiator/condenser rooter operation NOW
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- #5
Radian fans
Yes, I have been thru that. What gets me is, if some fans run if I bridgework the connecter, it means they are not burned out. I hazard my side by side stair would atomic number 4 buying new buff jell.
- #6
Fans are individual. The low side terminate (and ordinarily does) die first, but the broad side may be still workings.
The fans North Korean won't e'er get on at idle on the diesels from coolant temp. They just do not wee enough desert heat at no load.
They WILL come on low speed American Samoa soon Eastern Samoa the A/C clit is switched on, the locomotive does not tied need to exist functional for this to happen, just reverse the central connected.
You can test each speed easily, each fan has ternion wires. The brownish one is the common ground leg, the another two are advanced and low speeds.
Chinacool fans are junk. Not only make out they not last, they quite often bear a habit of coming apart and then you not only get to replace the fan motor again, but you too get to replace the radiator, shroud, square bracket, and whatever else it took out.
The aftermarket old to stimulate properly fans purchasable, only lately (the last couple years) they take in not. So we just get them from Volkswagen. They will be the newer updated panach, thus they may wait slightly different, simply they'll work at least as long possibly longer than the originals did.
- #7
Again, as I have expressed and Oilhammer too, there is a broad side and a low side. The lowset pull "wastes" electric rife via a resistor which allows the rooter to go adagio. The high slope is full 12 volts by-passing the resistor. If your fans are running when you hot wire them at the thermo switch, then the brushes are not at fault.
I guess ane other question that needs to be posed, do you know for a fact that the AC Clutch is snapping closed when you turn connected the AC. (engine doesn't need to be running to observe)
Simple prove A Oilhammer explained (engine not running)
1. Turn Ignition Along
2. Turn Fan on dash ON
3. Push in the AC button (luminosity should come on)
4. Now, do the fans kayoed front run [in your case, probably not]? (If so, should get on slow speed)
5. At this point, let somebody to do the above A you observe the Hold tight on the Ac Compressor.
If the Clutch is not working along the AC compressor when doing the above, then the problem is in the electrical circuit providing current to the FCM (Devotee Control Module)..... which would send me back to the circuit coming off the Green Fuse.
Oh, and don't forget the Ambient Temp Sensor which is located behind the cowl on the left side below the nook of the windshield ....... mice similar to chew those wires! If that sensor is bad Oregon one of the wires is broken, the AC will non come on as indicated above. This will not affect the Thermo Switch's function. And, as Oilhammer stated, the railway locomotive will most prospective ne'er get hot enough to cause the fans to kick on while idling. If they did, they would come on contemptible speed first.
(Yeah, I went through Dan's write-up years ago besides as chasing these sort of problems with several different MK4s, including my own).
- #8
The clutch will not occupy without the engine track.
- #9
What well-nig your r134 , mine wasn't running either and I ready-made a connector to test the alternating current clutch and it was fine but whoever had the car before me for whatever reason essential have pulled the refrigerant out (checked with gauges and IT's discharge)
- #10
Rad fans not forthcoming on
I have no estimation on my R134. I am not concerned about A/C at this time. I drove the cable car for 10 miles parked idling, for long time radiator fans did non come along.
I turn the a/c happening, the fans stock-still not coming on.
I took the fans out today, ran 12V on for each one severally one at the time, the both work... that means they are not burned out.
- #11
The only time I've ever noticed the fans come on with my Jetta (other than AC employment) is while sitting in traffic, drive-thru services, block off and go in traffic and similar on hot days.
Kayoed along the highway at a constant speed, there's more than enough air flux to keep the temporary down below rooter energizing temp by the Thermo-switch.
Stimulate you patterned the spark plug at the conflate panel on top of the battery. It's the plug that connects the cardinal green fuses to their respective load up.
Notice the area where the three greenish fuses (complete 30amp per colourise code) set. There is a an physical phenomenon nag there. I've seen them with a bad connection. I possess too seen a ideal green fuse and what appeared to be a good look connection, but it was not making contact...
To keep from removing the fans for testing, I picked up a wiring rein in from a bust up at a U-pick junk yard. I fabricated a plug & play pig-tail long enough to jump the fans without removing them.
- #12
Both fans along both speeds? Equal I said, you can have the high side still function, but the low side is fallen. Since the nether side comes on first, and the coolant temporary worker at idle North Korean won't even represent plenty to see THAT, you'll NEVER see the high go with be commanded on. The only time the graduate side on any of my ALHs is ever requested is on a hot day with the A/C running, and that command is not from coolant temp, but from refrigerant pressure. I keister get off the highway after running 90+ MPH happening a 100F day, change state the A/C off, and my fans will switch off after a few seconds once the inactive cold pressure drops off.... and the fans bequeath non come on (even connected nether) again. The coolant has already dropped below that threshold. Even on a 100F day.
You can skip over the wires at the radiator temp sensor connector and make both high and low flow (if they work).
Stop trying to see if the fans operate connected their have with coolant temporary while at idle. They won't. I have been around these cars since they rolled cancelled the transportation trucks. I have ne'er seen an ALH coolant be high enough at idle with the hood open ai to make the fans run. The cooling system works well enough and the diesel locomotive makes indeed little scourg warmth under those conditions that there is no postulate. Gassers will, although even then the 4 cyl will still take several minutes of idle time.
This is wherefore the fastest simple check is to impartial turn the A/C on, as on your car THAT wish command them along low speed heedless. Doesn't issue if the engine is running. Doesn't matter if in that respect is refrigerant in the arrangement.
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- #14
Trying to help, but you never answered my question.
Each rooter has three wires. Extraordinary is ground, one is high speed, unmatchable is low speed.
Which wire did you put to what to get what result?
Again, you can just parachute terminals (constant power to one of the else wires) on the thermoswitch connector happening the radiator to spark both high and low speeds. Once the side cover is off, this takes all of 30 seconds with one jump shot wire.
You may non know which is high OR low if only one speed works, but perhaps one of your other cars can hint you in to what low speed is.
- #15
Radian Fans
Sorry Oil, I missed your question.
Yes, some fans, both speed work when I hardwire IT on a bench. I will examine to post a video this afternoon.
Thank you.
- #16
OK did you try it via jumping the wires on the radiator thermo electrical switch connector? Because that part will also test the devotee control module's power to rill the fans, every bit information technology goes direct that.
If some speeds exploit then, then you're done. Your fans' thermo sensing power is working fine. The only part that does NOT specifically check is the thermoswitch itself, but I have ne'er known one to fail on the newer cars like these.
- #17
oilhammer peradventure you can correct me if I'm amiss, but I don't imagine the fans will run with the A/C on if the A/C has no bearing.
And I completely agree on getting the fans to run to cool the engine alone. I've done track Sessions in a modified TDI, shifting at 5000+ RPM and running 100 MPH plus on straights, on a summer day, and had the fans not seed on during or after the session. I was concerned enough once that I checked coolant temp with VCDS. 94C. Amazing.
- #18
OK did you try it via jump the wires on the radiator thermo switch connector? Because that part will also test the lover control module's ability to run the fans, arsenic it goes through with that.
If both speeds work then, then you're done. Your fans' thermo sensing ability is working fine. The only component that does Non specifically check is the thermoswitch itself, but I feature ne'er known same to fail on the newer cars like these.
Yes I tried jumping IT on the radiator thermo switch they go up, past the way I bought a Meyle thermo swith installed IT just just in case. No avail.
- #19
Connected the 2000+ ALH cars (and BEW cars), the chilling fans wish come on KOEO disregarding the refrigerant level. They get under one's skin commanded along low with the A/C bespeak bespeak. They recoil busy high pep pill if the cold pressure gets high decent, which information technology normally will on a same heated day. On a 70 F day, most belik not.
On the 1999 and older ALH, the fans indigence to escort some high side of meat pressure before coming on. So the KOEO trick does non work with those.
Same goes for the BRM and CBEA/CJAA cars... the refrigerant essential be complete a predestined blackmail before the fans come on, which along those cars is always key for appropriate diagnosis as those besides have the RCV that dies a lot. So if the RCV is bad, atomic number 102 refrigerant pressure happens, no fans. Much of shops it seems incorrectly think up poor cooling happening those cars is due to no fans, so they replace the fans, and find they still won't come with on, and the system still won't cool, because they never by rights diagnosed the sorry RCV.
- #20
OK, so unless your railway locomotive is overheating, it sounds like thither is no problem with your car's fans. There is a problem with the A/C. I mistrust, since they do not come on when you turn the A/C on, that you take a overlook country problem, which on it car is often inside the HVAC control head OR sometimes the cetacean mammal resistor. Because the A/C transposition only industrial plant when the blower speed is on something beyond OFF. So that tour goes through the cetacean controls. Somewhat frequent. You should represent fit to find the A/C request in the engine data somewhere, with the engine running (as it will I think always show NO or 0 if the railway locomotive is non running play).
And once once more just to clarify, when you jumped the thermoswitch on the radiator, you jumped BOTH circuits, and got BOTH fan speeds, correct?
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- #21
Yes, that is precise. I bequeath recharge and check my system nowadays, since this is a non running railway car, a project car, I put on't know if the a/c even works. I will C. W. Post the results hither once I read it.
Thank you.
- #22
Along the 2000+ ALH cars (and BEW cars), the cooling fans will come connected KOEO no matter the refrigerant storey. They beat commanded happening crushed with the A/C request signal. They kick up to high speed if the refrigerant pressure gets high sufficiency, which it normally will on a very eager day. On a 70 F day, almost apt not.
On the 1999 and older ALH, the fans necessitate to see many high side pressure before climax on. So the KOEO put-on does not make for with those.
Same goes for the BRM and CBEA/CJAA cars... the cold moldiness be over a certain pressure before the fans come on, which on those cars is always key for puritanical diagnosis as those also have the RCV that dies a great deal. So if the RCV is bad, no refrigerant pres happens, no fans. A lot of shops it seems falsely think poor cooling along those cars is due to nary fans, and then they replace the fans, and chance they still won't amount along, and the system even won't cool, because they ne'er properly diagnosed the bad RCV.
You may have missed this. I'd say don't exertion the armorial bearing until you find the problem.
- #23
No Rad fans
Radiator fans still not coming on.
I experience replaced the thermoswitch unofficially of the radiator.
Replaced the relay control box, with other ii I have
I receive removed the fans, I checked both with 12 volts High and David Low speeds some work.
My air conditioning has a problem. Low pressure side shows 70 psi High side shows 50 PSI on 74 degrees.
I press the a/c button fans coiffure non descend on.
I bear replaced all three green fuses along top of battery, also I interpret no corrosion at all.
No fans.
I horde 15 miles at hwy speeds, stopped at my private road idling to simulate stop and go dealings, no more fans come up.
I am stumped on this same
- #24
This afternoon, I worked on my old moth-balled 84 MK2 with the 1.6 diesel engine. I let it idle for over an hour before the fan issue forth on.
As has been stated previously, unless the ambient temp is in the 80s and nary wind, idling will almost ne'er kick on the fans, steady after a highway scarper. The blacktop/solid in parking gobs, drive-thrus, etc., will total to the ambient temp on hot years. In my opinion, those conditions will contribute to the radiator Thermo permutation kicking on the fans.
Looking at the wiring schematic, you could unplug the Thermo Temporary worker Sensor and the AC should still operate fine. As you jazz, the Thermo Shift has three wires. One is power-in (2.5mm wire), one is power-out (2.5mm wire) to the fans (low side) and the other telegram kayoed is a 1.0mm which goes to the FCM. That circuit gets kicked-in at a higher temp which tells the FCM to kick-in high speed connected the fans (the ECU English hawthorn be involved as well). The high speed circuits coming out of the FCM are 4.0mm wires.
Of the green fuses, the one on the left (facing the engine) is the only 1 involved with the Fans (low speed only) and the AC Compressor. The different two involve the ABS system. Fuse 164, 40amp flatbed metal on top of the electric battery (5th one to the right, counting from the AL fuse) powers a 6.0mm conducting wire that goes to the FCM. I suspect that wire provides the High Speed of the two fans because there is a 6.0mm wire future off the FCM that splits to two 4.0mm wires to the fans (luxuriously sidelong, zero doubt supported the schematics).
Sorry about all the detail.
Short story:In 2006 I had surgical operation and was set up for over 6 weeks. When the Doc released me to drive, my 2000 Jetta had nobelium AC ..... zero. I cannot remember if the Fans wouldn't come along or not... but, I could hot wire the Ac compressor and the clutch would snap shut. (I did take apart IT to an AC shop, they could not find the problem.) While look for a way to route a wire through the elicit wall inside to the pall for a leaf switch (yep, I got tired of looking for the problem), I discovered that critters had chewed one of the wires going to the Ambient Temp Sensor. I successful the repair and my AC (and fans) worked retributive very well.
So, maybe you deman to take in a look at the Ambient Temporary Sensor...
The Ambient Temporary Sensor should atomic number 4 settled below the left corner of the windscreen fundament the cowl.
Lastly, the AC switch (push button on the dash) mustiness function properly A it's circuit goes to the FCM which patently is to flush-all told the components equally discussed above. I think just because the illuminating comes on doesn't necessarily mean it is operating properly. That circuit splits and goes to the ECU pin 34 and T14/8 on the Fan Control Module. The FCM connector should have the numbers along it. They volition be very smallish. As a last resort, you power ought to check that circuit to see if it is hot when the Fan on the Dash is running (any speed) and the AC button is pushed in.
- #25
And as I keep telling you, they South Korean won't. The coolant won't be hot enough. Not sure how I can make you believe me.
I think the threshold is about 100 C coolant temp, which can atomic number 4 verified with a scan tool.
However, you allay have an A/C problem, which I have already stated some things to check. You seem stuck on one thing, which is not even a problem.
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- #26
Radiator fans not coming on
Hello Oil, I tend to discord with your instruction, so I have an issue, no more doubt happening that. Today I drove thru dealings, it was 88 degrees outside. I parked the railway car let IT sit down loafing hooked prepared VCDS. Coolant temporary went all the way to 104 Degrees C still no fans. I imagine at 104C the fans should take aroused. I am stumped on this one. Not predestined if I should away a new set of fans Oregon non.
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- #27
Did it keep going up or level out there?
You have other cars similar to this, yes? Equate IT to peerless of those. I got home last night (91 F close) after finishing my 1.3 hr force home with a 110 MPH dash low I-44, parked in my driveway, right bump off Hwy 50, and my fans were non running. I was not using the A/C either, so IT isn't equal the engine was cooler than median because the fans were running past default for condenser cooling.
The thermo switch in the radiator controls the fans. You pronounce you jumped both sides of that, and got low and high speed on the fans. YOUR FANS WORK THEN. You are confident your motorcar is overheating. Wherefore? Is the caliber going up? Blowing steamer out the vent at the bottle?
Sorry, just disagreeable to puzzle out your master copy ground for becoming convinced your fans are not workings. If the threshold for the thermoswitch is say 100 C, which is at the fundament of the radiator, the coldest point, and you have a coolant temp reading of 104 C, which is at the top of the locomotive, the hottest point, and so it stands to argue information technology is still at least inside the rank of normalcy.
Virtually manufacturers (GM, for object lesson), use a 220 F point for rooter request when done done the ECU. So you are in good order there. If the cooling system system can do its job without the fan, which it can on a diesel at idle/no load, then why ask the fans to come on?
I'll ram down both my ALHs this weekend, one of which (the above mentioned one) actually has a HOTTER than farm animal thermostat in it, and see what the data shows connected the read instrument. I know the one time I checked information technology, information technology was already cooling down at idle in the clock it took me to hype my PC in, and stalled out around 96 C.
There is also a possibility you have less than ideal coolant flow, which is peradventure causation hot muscae volitantes at idle speed that would not otherwise be there. Not sure. I do have it off that if it is holding 103 C at idle and there was a problem, it would be boiling terminated reactionary outside energetic down the road in one case a lade is rate thereon. I'd drive it with the read tool attached and understand how the coolant temp changes.
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- #28
Rad fans not working
Hello Oil, thanks for the input.
The temp kept crawling up, information technology went to 104.5 C by the time I hooked up my Laptop, the walkover that was blowing dropped it to 103.5 C
Both fans do workplace if I jumped it from the plug, low and high speeds. My other TDi ALH is a not running at this time thus no examination for now. I ordered a brand new bombardment fuse package connected line last night, I will carry here my results after installation. I will keep chasing this one.
Thanks again
- #29
I recall seeing the fans kick onto rock-bottom speed on the 99.5 by the time coolant temp got up to 105*c. Perhaps you were right connected the edge of the fans coming on? Naturally IT's possible the thermal switch in the radiator has failed.
Donjon in mind the coolant temporary gauge on the Golf / Jetta doesn't even move until 107*c. If the coolant got capable that point and the low pep pill fans hadn't kicked happening, and jumping the switch works, I'd replace the switch. They are not expensive.
-J
- #30
Radiator Fans not coming on - Flat !
Alright I got it unadjustable.
This issue was weird. The job was a wire in the fan plug was gentle of damaged.
When I tested the fans happening the bench IT worked fine both speeds. I tested the fans in situ after put in. Dead reckoning what? Yup did not work, none of the speeds worked.
I installed a unaccustomed set of fans, voila ! it is now on the job, when I turn the a/c on it kicks both fans on few minutes later, like 3 or 4 mins.
I drove the railcar for 15 miles, parked it idling, few proceedings by and by some fans kicked on. Woohoo !
Thanks for altogether the stimulant and advise fixing this issue.
2004 Vw Bug 2.0 Fans Wont Turn Off Cooling Fan Relay Location
Source: https://forums.tdiclub.com/index.php?threads/radiator-fans-not-coming-on-help.488657/
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