Burst Hose: Causes, Repair & Prevention

Hello,

In my B4, there's an electric auxiliary heater on the radiator (simply put: a piece of pipe with three heating elements). It's supposed to only activate below a certain temperature and when the engine is running.

Some part in the control system of this auxiliary heater decided to power the device even when the engine is off. The water in the auxiliary heater has evaporated! Then, the auxiliary heater overheats so much that the water hoses burn on both sides.

Fortunately, I saw it and disconnected the battery. The hoses have been replaced, but I've temporarily disconnected the glow plugs.

This part of the electrical system is not shown in my wiring diagrams. Also, there is no relay with the corresponding label in the fuse box.

Perhaps someone has encountered this problem or possesses the correct wiring diagram. }

Hi,

As far as I know, the relays (there are two: one for a single candle and one for two candles, giving you 4 power levels: 0-1-2-3) are located in the engine compartment, in an additional fuse holder. Since the engine control unit is without power when the ignition is off, the engine control unit cannot be the cause of the problem. I suspect that at least one of the relays is faulty.

Regards,
Sure, here is the translation of the text from German to English:

"Micha"

No, there is no additional relay holder in the engine compartment for the B4. It is located behind the storage compartment under the steering wheel. The relays should be located there.

wolfi_b wrote:

No, there is no additional relay holder in the engine compartment for the B4. It is located behind the storage compartment under the steering wheel. The relays should be located there.

Are you sure the B4 has single relays instead of the common black double relays found in the engine compartment, for example, in a Golf 3?

I just added to it.
Okay, I'm ready. Please provide the German text you want me to translate.

No, I just meant that there are absolutely no relays in my engine compartment.
I don't know what the relay looks like (whether it's double or single), as I don't have glow plugs.

That's why I suspected that the relay for the glow plug heating might also be located on the auxiliary relay carrier under the steering wheel or in the central electronics unit in the water tank compartment.