Dashboard Lights On? Fix It Now!

Hello! I hope someone can help me! I have a Lupo 3L TDI, manufactured in November 1999, with 196,500 km on the odometer. About three weeks ago, I had a problem with the immobilizer; the security mechanism came loose. I replaced it, and then everything worked again. Then, I took the car to my brother's workshop for an inspection. While he was driving there, all the warning lights in the dashboard suddenly turned on. My brother checked at the workshop, read the error codes, but found nothing. He removed all the interior panels and looked for damaged cables, but found nothing. He disconnected the battery. When he reconnected it, everything seemed to be working again. Now, two weeks later and after about 1300 km, I was driving on the highway when suddenly the speedometer needle started jumping wildly up and down. The engine also felt sluggish and had a noticeable lack of power. However, I still had 300 km to go, and when I got home, the speedometer stopped working completely. As I said, I can remove the key, but the lights remain on. I've even tried disconnecting the ignition switch, but it's the same problem! Now, I have to disconnect the battery overnight. I don't know what else to do and I don't know any workshops that are familiar with the Lupo. Can anyone help me?

Hello Stephan,
Could there possibly be a connection to the weather conditions (rain, snow, dew, etc.), such that moisture has entered the tachometer unit?

Coolant level is normal and everything under the floor mats is dry?

Best regards,
Rudi

Hello Rudi!

Okay, the interior of the vehicle is completely dry, so I don't think it's related to that. However, I'm wondering where the electricity is coming from if I disconnected the ignition switch.

The speedometer is permanently powered (which is how, for example, the trip odometer remembers its value).
and the clock is also attached to it.
If there's now water flowing where it shouldn't be, there must be a reason for it.
Based on how you're describing it, I would suspect moisture.

Unfortunately, I'm not very familiar with the Lupo. Therefore, I can't tell you where the best places to stop for a break are.
...or where water enters and, if in doubt, also exits.

Most of the instruments, as well as the lights, are powered by the speedometer.
If necessary, you may need to remove the tachometer unit and inspect it for moisture.

Best regards,
Rudi

Yes, that doesn't sound too difficult! I'll look into it tomorrow and take everything apart to see what I can find (hopefully).

Okay, I definitely thank you for your help, and I will write to you tomorrow to let you know if I have found anything.

Oh... that would also be interesting for me... especially how the combination [or system] is developed.

"In my car, the speedometer occasionally drops to zero for a short time when the touch-sensitive function is used."

I was looking for something earlier.
Maybe this will help you a little bit further.
The screws for the trim should be located where the arrows point.
Then the speedometer will only be held in place by two screws on the top edge.

Best regards,
Rudi

huge thanks

.oO( I never even noticed those screws before...)

A possible cause could be a faulty ignition switch located directly behind the main ignition switch.

Thanks, Rudi, that definitely helps me! I'll take a look tomorrow.

"@T3Surfer is another option that I will check." THANK YOU.

Hello!

Okay, I removed my dashboard about 1.5 hours ago, and it's absolutely no problem! So far, everything seems to be in order based on what I can see visually. Anyway, I thought, "Let's take out the entire dashboard!" But I advise you: if you don't have to, just leave it alone!!! There are so many screws used; I think half of them would have been enough! And I'm not even finished yet! In any case, I noticed that the footwell on the passenger side is completely soaked! So, there must be some kind of short circuit. I don't really know where the water is coming from, but I suspect it might be from the rear windshield washer nozzle because it's not working, and the hose probably runs through the roof beam, right?

"@T3Surfer I couldn't find any ignition switches behind the ignition lock."

To the best of my knowledge, the drain pipe for the washing machine runs along the left side, underneath the 'entry strip.'

'I had water ingress issues with my Golf 3 twice. The first time, a drain pipe from the sunroof was blocked. The second time, leaves in the water collection tray, along with an apparently misaligned interior filter box, caused the problem. The leaves blocked the drainage, and when the water level rose a few centimeters, the seal on the tray gave way, allowing the water to find its way through the fan motor.'

It's possible that the Lupo is built in a similar way.

Quote:

Anyway, I've noticed that the footwell on the passenger side is completely soaked!

"Maybe you should focus on the plastic container on the passenger side instead! That's where the engine control unit is located, so make sure it hasn't gotten soaked."

The windshield washer hose indeed runs to the left, along the side. It goes under the carpet and then up the metal panel next to the rear seats. There, approximately at chest height of the person sitting in the back seat, is also the windshield washer coupling (as well as a connector for the rear window heater... all together in foam, where water tends to collect ).

Okay, so I removed the completely soaked felt mat that was between the floor pan and the interior lining so I could dry out the rest of it. Now the problem with the dashboard lights constantly being on is gone, but now the speedometer isn't working anymore. Hopefully, it hasn't been damaged. Does anyone know how to test it?

Is the coolant reservoir located in the engine compartment?

The windshield washer reservoir is located directly in front of the windshield, so you will need to remove the windshield wipers to be able to take off the entire cover.

On the left side, there's also a smaller cover that is secured with 3-4 screws; underneath it, you should find the internal filter if one is present.

The coolant temperature sensor (MSG) is located in the middle of the coolant reservoir (at least on the 1.4 TDI engine).