Charging voltage Renault Clio III gasoline 2009

Hi.

The text is about a neighbor (over 70) who occasionally needs help changing light bulbs in his Renault Clio.

"Recently, the H1 and H7 brand-name headlight bulbs have only been lasting a few weeks before they practically burn out. Just yesterday, after 3 weeks, the glass bulb was already discolored black/blue."

I then measured the on-board voltage with the lights and normal accessories turned on. It remained almost constant at 14.6 volts, both at idle and when accelerating, as measured with a Voltcraft and a Testo multimeter.

"It seems too high to me, and after almost 210,000 km, I suspect the alternator or its regulator. I recall a maximum of 14.4 volts from previous experiences, and my experience with vehicles from the VW group usually puts the voltage in the range of 13.5 to a maximum of 14 volts."

What do the experts say?

Thank you.

Hi,
Perhaps the voltage at the halogen lamps is too low due to age-related contact resistance. This would prevent them from getting hot enough, and the filling would not regenerate. The vaporized metal then deposits on the piston.
hg
Herbert.

Hello!

In older, simpler cars, the voltage regulator on the alternator controls the on-board voltage.
Normally, and with the exception of very old vehicles, it also regulates temperature-dependent functions to a certain extent.

When it's very cold in the winter, it outputs around 14.4 volts.
At the current temperatures, I would expect a voltage of approximately 14.15 V.

To the best of my knowledge, the light bulbs are designed for 13.8 V. Due to the transition resistance.

The 14.6V reading is not normal, that's for sure.
It also doesn't explain the rapid wear and tear on the lamps. It's not that far off, actually.

I've already measured 17 volts on cars. They then tended to have problems with the battery, or they wondered why the windshield wipers were moving so fast.

I can imagine that the tension might sometimes be even greater.

Tip:
Okay, please order a small voltage indicator from the Chinese supplier for a few euros. It's the type that plugs into the cigarette lighter, so you can check the voltage occasionally even during normal use.

To the best of my knowledge, the light sources are designed to operate at 13.2V.
In older vehicles, the wiring was typically thin and long, which resulted in a significant voltage drop between the battery/ground and the light source.

In newer vehicles, a control unit regulates the output of the light source using Pulse Width Modulation (PWM). In this case, the light is driven at 100% PWM (i.e., nearly the battery voltage) without the use of a motor. With a generator, the PWM ratio will then be approximately 80-90%, depending on the battery voltage.

In short: While the voltage at the battery may seem high, it has nothing to do with the voltage at the light source. So, measure directly at the light source using a good multimeter (if the vehicle already has a corresponding control unit, the meter must be able to display True RMS values).

With older vehicles, resourceful hobbyists often installed a thicker power cable and a relay with a thick positive cable to the headlights. This resulted in significantly more brightness, but of course, also a shorter lifespan.

However, most of the lamp fixtures I'm familiar with still suffer from vibrations. If a screw is missing on the mounting bracket, or the motor mounts are worn out, or something is rusted, it can quickly lead to problems. Make sure to check that as well.

Do only the H1/H4 bulbs burn out, or also the tail lights? This provides insight into whether the issue is related to voltage fluctuations rather than vibration.

Regards,
Guste.

In my experience, the parking lights and license plate lights are often the first components to fail due to voltage surges. Very often, they show signs of damage with small beads of melted material at the ends of the burned-out filament. H7 bulbs also exhibit this characteristic quite prominently.


My Smart car, with its faulty battery, also showed over 17 volts on a device plugged into the cigarette lighter socket. With the built-in faulty battery, the car wouldn't start. It would start with a jump start, but the voltage would rise after the jump start cables were removed. The transmission control malfunctioned, and the engine reluctantly increased its speed.

The first step to fix the problem was to disconnect the faulty battery. I drove for a few days with a battery placed in the passenger footwell, connected to jump leads. Besides some defective parking light bulbs and an issue with the clock, there were no other problems. A new battery was installed, and that seemed to fix it. Unfortunately, the car didn't clear the error codes from the airbag and ABS systems, so they had to be erased manually. I had to re-pair the TV remote controls.

*secured to the center console with a strap.

Thank you for the information and tips. If possible, I will measure the voltage at the terminals connected to the light bulbs on the car. I believe my Testo measuring device will provide accurate readings.

No one tinkered with the car; it belongs to a retired couple who bought it new. They usually take it to the authorized service center for any repairs. However, when it comes to replacing the glow plugs, they do it themselves, helping each other out with small tasks.

In recent weeks, the issue has only affected the H1 and H7 incandescent bulbs in the main headlights.

Let me know if there's any news.

Thank you.

Quote:

In recent weeks, this issue has only affected the H1 and H7 incandescent bulbs in the main headlights

.
Check from the back of the headlights to see if the reflector inserts are mostly securely in place. I have more than a little play, then it rattles the lamps.

H1 bulbs are actually the ones used for the high beam headlights, right? They rarely break down because they typically don't get used for very long.