Climatronic Compressor: Shuts Off Every 60 Seconds? Help!

I have a Volkswagen Passat 3B TDI Variant, manufactured in 2000. The engine code is 'AHH', and I'm having major problems with the Climatronic system.

I've read through the forum and used the search function, but unfortunately, I haven't found a suitable answer for my problem.

My problem:

The Climatronic system is malfunctioning, and it's manifesting in the following way: When I'm stopped at a traffic light and the engine is idling, the Climatronic air conditioning compressor turns on and off repeatedly, every 40-60 seconds. The interior isn't even cool yet, but the compressor is constantly switching on and off. This is particularly noticeable when it's very hot outside, for example, with temperatures of 29-32°C. It's also worth noting that one of the electric fans isn't working at all; could this be the cause?

I'm also not satisfied with the performance of my cooling system. It doesn't cool as well. When I set it to 'LOW,' it does cool, but I have a feeling it's not running at full power. My friend also has a cooling system, and his freezes his fingers, but mine doesn't get that cold.

I had the air conditioning system serviced a week ago, and I can't explain any of this. It's worth mentioning that the cabin air filter is new, and sometimes the display on the climate control unit flashes for 15 seconds.

When I check the climacodes, it always shows '444', which means no error.

Please help if possible THANK YOU!

Take a look inside here.

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

CU Gremlin.

Thank you, Gremlin, for your help.

Okay, I had already read this post before, and today I took my car to the VW dealership to see if I was experiencing the same problem.

I'm still wondering when the electric fan on the radiator will turn on.

Thank you for the answers.


P.S. I will report on what caused it.

Hello everyone!

I just came from the VW workshop, and the diagnosis is as follows:

1. Electric fan broken, part number 8DO-959-455C.

Fuse blown, part number N 102-51901. It is a 40A fuse.

I checked, but the fuse doesn't fit in the fuse box. Where should the fuse go?

I ordered the new electric fan from my parts dealer, and it cost me 150 euros. If I had ordered it from VW, the whole thing would have cost me 500 euros.

Okay, so far so good, but the story isn't finished yet, so I'll get back to you when everything is done, and then I'll report back here to let you know if everything is working normally again.

Thank you .

Okay, that's also a potential cause of the problem. If the fans aren't running when the system is idle, the capacitor will overheat, which increases the pressure in the system and causes it to shut down.

The fans usually run at a low speed once the air conditioning is turned on.

The fuse should be located on the relay carrier, and I believe it's in the same location as in the Passat, which is on the left side under the dashboard (remove the cover above the pedals).

How does the cooling performance fare on long journeys? Is it reasonably good?

CU Gremlin.

Hi.

Thank you, Gremlin .

Okay, so when you're driving the car, the air conditioning runs 'normally,' meaning the compressor is running constantly, and it's cooling, but the cooling performance isn't particularly good (compared to another vehicle my colleague has). Maybe it's all related to the fact that the fan is stuck .

Anyway, I have an appointment on Wednesday for a fan replacement, so I'll find out the truth at the latest then.

Oh, what must happen for a 40 A fuse to blow? I've been racking my brains about this since I came back from the workshop.

Please cross your fingers that this thing starts working normally again.

Thank you all .

Hi!
Doesn't the fuse for the 2000 Passat also already exist as a metal strip fuse on the battery? I would be very surprised to find it in the control unit.
Otherwise, I completely agree with Gremlin. I can also imagine that the cooling performance might increase again with working fans (at least at slower speeds), as the refrigerant would completely liquefy again at the condenser.
Is it absolutely certain that the motor is really defective? Otherwise, I would first check the cables, make sure the fan is running freely, and then replace the fuse. I think it's worth a try...

Best regards,
Dirk.

Hi.
Thank you for the advice, brezelmann01 .

I also wanted to check if the motor is actually broken or if it's just a blown fuse. However, I'm short on time today and don't have a fuse on hand, so I'll probably have to do it tomorrow, even though I'd rather do it right now. Well, I'll just have to be patient until tomorrow.

I'll report back whether the motor is actually damaged, but: if the fuse is already blown, then the motor should still be okay, right? After all, fuses are also there to protect other components.

I'm not sure, but I'll check it out, as I said.

Thank you all .

Therefore, fuses also serve to protect other components.


Not really... they are actually meant to protect against cable fires.

If, for example, the fan motor is difficult to turn and the winding melts, it will cause a short circuit to ground, and then the fuse will blow as a CONSEQUENCE of a component defect!

CU Gremlin.

OK, thank you Gremlin and everyone who has helped me here .

So, now I have a very good news .

It's just the fuse that blew, everything else is fine!

I spent quite a long time searching and working to figure this out.

@Gremlin: You were right. The fuse was located directly above the pedals, so I had to remove the entire cover.

@brezelmann_01: Thanks for the tip!

Conclusion: The following causes may be responsible for the compressor of the air conditioning system turning on and off in short intervals:

1. Pressure relief valve.

2. Overcrowding.

3. Fuse.

4. E-fans.

Now I'm a little bit smarter, and I have you and this great forum to thank for it!

Thank you very much.

He he, did I get a little too excited too soon ?

Okay, let's start from the beginning again. The fuse blew again, so something's not right. The electric fan worked with the new fuse, but as I said, it blew again.

Okay, here's the translation:

'Okay, another question: what should I be looking for? What could be broken if the fuse keeps blowing? Is it possible that the electric fan is broken even though it's spinning?'

I am very grateful for any helpful advice.

Yes, the fan could still be broken even if it's spinning.

A motor typically has multiple windings that are offset from each other. Depending on the motor's position, one winding is always active. If one winding has a significantly lower resistance, the motor will draw considerably more current at a specific position. Once the motor starts rotating, this becomes less of an issue, as only a brief current pulse occurs, which is usually not enough to blow the fuse. However, if the fan motor remains in a position where the low-resistance winding is activated when the motor is turned on, this can cause the fuse to blow. This probability is further increased because the low-resistance winding often has a shorter effective length, which means it can generate less magnetic force. As a result, the fan motor may have difficulty starting or may not start at all. This prolonged high current flow increases the likelihood of the fuse melting.

Translation:
Review:
Measure the resistance of the fan motor while slowly rotating the fan. You will likely find that the resistance is particularly low at one specific point.

Remedy:
Case 1: It's possible that only the contact surface of each coil is completely filled with conductive carbon residue from the carbon contacts. This would cause multiple coils to be activated at one point --> resulting in excessive current --> causing the fuse to blow. Cleaning the gaps between the coil terminals might help, but it usually doesn't last long.
Case 2: If a winding is burnt, then there's really only one thing that helps: rewinding . However, neither you nor I would likely be able to do that properly, so the best solution is probably to replace it.

Regards,
Sure, here's the translation:

"Guste" is a German word that means "gust" or "gust of wind." It can also be used to describe a sudden burst of something, such as laughter or anger.

Thank you very much, Guste .

You put a lot of effort into explaining things to me, so thank you very much, and also to everyone else.

I also asked a few people, and of course, I got the same answer.

So, don't just put in new fans and then it should work.

Thank you again.

Best regards,