Sparks from the soldering iron?

Good evening!

I need an explanation for a peculiar phenomenon.
Last week, I was struggling with the lighting system on an old Peugeot 107.
The first observation was that there was no ground connection reaching the H4 headlight.
So, I cut the ground wire and connected it to a reliable grounding point.
It didn't help. As I later found out, ATU had already tried to fix it before, and apparently blew a fuse in the process. It's also a bit of a strange electrical system.

To fix it, since I had cut it a bit short, the only option was to carefully solder it back together.
No problem, thought, done.
The car was partially raised on a lift, resting on rubber supports. Electrically, it is completely isolated.
When I touched the cable with the soldering iron, it sparked, although it was a small spark.
Tried it three more times, same result, sparks.
It's roughly equivalent to plugging in a 15-watt light bulb.

Since the soldering iron was hot, I unplugged it from the power outlet, and then used the residual heat to make a good solder joint. When the soldering iron was disconnected from the power supply, nothing worked anymore.
The car's electronics survived, and nothing broke.

Of course, I had the soldering iron checked by an electrician.
He brought it back to me today, saying that everything is okay.
He would have even tested it with 3000 V after an initial, standard inspection, and he couldn't detect anything unusual.

Can someone write something about it for me?
I just don't understand it.

Was was still connected to the car, for example, a charging device? Sometimes, even a fluorescent tube lying inside the car could cause similar effects. Next time this happens, bring a measuring device and measure the voltage difference between the two points and the current flowing through them. If it works, then there's definitely something to it.

...and: German and Austrian. Plug connectors (and 2-pin Euro plugs) can be inserted into the socket in two ways.

Please remember that this will swap the phase and neutral wires, which can cause differences depending on the insulation or construction of the device.

What type of soldering iron is it?
Soldering iron or soldering station?
Does the soldering station have a Euro plug or a Schuko plug?

Question: What happens if you touch the soldering iron to the protective contacts of an electrical outlet? Small spark?

It's also possible that the car acted like a capacitor and was fed with a small alternating current through the soldering iron tip (capacitive coupling between the live/neutral wires and the soldering tip).

Car = a large conductive surface that is constantly being recharged.

Greetings.
Guste.

Hello everyone!

Okay, I'll chime in too .

G. Steffen writes about "soldering irons" and states that anything with a heating element that operates on 230V and is touchable corresponds to protection class I, which means it has a protective earth connection plug.

The car remains on a lift, also protected by safety class I, which draws its power from a source located elsewhere, i.e., further away.
Rubber buffers do not necessarily have to be completely electrically insulating.

Since he describes the phenomenon using a "15W light bulb," we're talking about 1A or more, and it's repeatable three times, so it's probably not a capacitive issue *I guess*.

My theory: G. Steffen lives in a rural area, where the TT network configuration is likely the standard.
By soldering, he created a connection between the ground wire of his (soldering iron) power outlet and the ground wire of his lift platform, which ultimately led to what is known as... Potential equalization currents could have been induced, which could potentially reach several amperes, while still resulting in a harmless touch voltage.
Network technicians are familiar with this when they need to connect PCs that are geographically dispersed via a LAN.
I personally can't explain it any other way, although the soldering iron seems to have passed the ISO test.

Regarding the actual issue: How can you initially have no mass on the H4, then suddenly have mass, but it still doesn't work? Was was this even measured properly?

Best regards from Munich!

Hello!

It appears I have a TN-C-S system, and the electrical system is regularly inspected by a qualified electrician. There's no junk or DIY projects here.
I really value having things be neat and tidy.

DieselBär30x wrote:

Regarding the actual issue: How can you initially have no mass on the H4, then suddenly have mass, but it still doesn't work? Was was this even measured properly?

Well, it's been measured accurately, but with that car, the lighting system is a technology that I haven't fully understood yet. I eventually accepted that it was working again.
There's definitely a relay involved there, which apparently also connects the ground wire to the headlights. And the volume is likely also secured.
I didn't expect such strange technology.

Hi G.Steffen!

Please try recreating the scenario again, but this time without using the baguette bowl. Alternatively, try soldering at the lifting platform, specifically on a shiny metal part.
(if possible, at the same time of day)

All-pole disconnection of an H4 lamp??
I may not understand it either, but I am also very impressed by the red wine technique .

Best regards from Munich!

DieselBär30x wrote:

Hi G.Steffen! Please try recreating the scenario again, but this time without using the baguette bowl. Alternatively, try soldering at the lifting platform, specifically on a shiny metal part. (if possible, at the same time of day)

Hi!

Yes, I will.
I prematurely bought a new soldering iron.
That would then be suitable for comparison purposes.

I will also be taking the suspicious soldering iron with me to work again.
and have it inspected by our electrical technicians.

I will report!

"But surely he didn't do that from the factory itself; the French and the electricity industry have never been friends..."
Is this the original owner, or has someone else already "optimized" it, and are the French innocent? Don't end up with a new construction site right behind an old one!

If it is actually a Peugeot 107, then you essentially have a Toyota in front of you, which was and is available to buy under the names Aygo, C1, or 107. Its interior electronics are bus-controlled, which is recognizable by the 'thick' steering wheel controls. The headlights are relay-controlled and, up to that point, are even diagnosable (with the OEM tester). I don't know for sure whether these things actually switch the headlight bulbs to the low beam setting.

The Peugeot 106, or Citroen Saxo, had versions with a bus control system (and "thick" steering column trim) and versions without (with "thin" steering column trim). The electrical system of the latter only becomes understandable after a few glasses of good French red wine. Many things were built under enormous cost-cutting measures, and this is noticeable in the cable cross-sections of 0.5 mm for headlights and the overall rigid wire insulation. Cable strands subjected to vibration were prone to breaking, and they often broke near the mounting bracket if they were not securely fastened.

Hello!
@ Bärli:
Okay, so I plugged in both the old soldering iron and the new one I bought, and I tried them out on another car on the lift, but nothing works.
I tried both methods, using the soldering iron both when it was cold and when it was fully heated.
Around the same time, I also tested it directly on the bare metal parts of the lift platform, with no results.
I also used the same extension cord.
Something must be wrong with the car, but luckily, I didn't break anything.

@ Matthias:
Well, ATU had already tried to fix the light before, but apparently they couldn't find the defective fuse and gave up. That's all I know. Everything seems to be working now, but I'm not really sure why the fuse blew, or what ATU even did before.

@ Hat Driver:
Yes, the cables to the headlights are very thin, about the same thickness as the ones in my Golf 2 for the parking light.
But then, the hard insulation isn't really a problem, because the cable will get warm during operation due to its small cross-section, and the insulation will become soft again because of the heat...
One could laugh about it if it weren't so sad.