Headlights flickering when driving or stationary

I have a 2006 1400cc petrol, manual, C3. For long enough now I have had the headlights flickering whilst I am both driving and stationary.
Recently my son was with me and he could hear a ticking sound coming from the glove box area whenever the lights flickered. The noise was louder when he opened the glove box. However since then I have not heard the ticking, but the flickering is still there. Another thing, when it occurs, the engine seems to " faulter " slightly. I have had a new alternator fitted recently but this fault was there before and still after. Has anyone had a similar experience? Or can anyone suggest a cure please?
Thank you. Peter.

Pete C wrote: ↑Wed Nov 11, 2020 3:38 pm I have a 2006 1400cc petrol, manual, C3. For long enough now I have had the headlights flickering whilst I am both driving and stationary.
Recently my son was with me and he could hear a ticking sound coming from the glove box area whenever the lights flickered. The noise was louder when he opened the glove box. However since then I have not heard the ticking, but the flickering is still there. Another thing, when it occurs, the engine seems to " faulter " slightly. I have had a new alternator fitted recently but this fault was there before and still after. Has anyone had a similar experience? Or can anyone suggest a cure please?
Thank you. Peter.

Hi

The headlights are controlled by the BSM - the fusebox under the bonnet.

So to get a relay clicking in the BSI (glove box fuse box) there is something quite fundamental not right. It even affects the running of the engine.

As you suggested, alternator, but this has been changed.

You still may have a charge fault, so was the battery fully tested before changing the alternator?

It can be quite simple to check alternator voltage output with a multimeter at the battery terminals and you can monitor this output while the flickering happens. It may or may not show up at the battery.

There may well be a poor connection on an earth, particularly around the battery area (under the battery tray etc).

I would start looking at the major electrical circuits like battery, earth, alternator because you have lights and engine both affected.

If you wanted to try and isolate a potential drain that is causing it, try pulling a fuse at a time to see if the light flickering and engine faltering stops.

BSM fuses and BSI fuses are listed for the 2006 (facelift) models.

HI , thank you for the suggestions, I will try what you have stated. Just as a recap, before the alternator was changed I tested the output at the battery and it was around 14 volts. Also I plugged in one of those cheapy alternator testers ( Lidl,s finest ) and it showed up the voltage surge as the lights flickered. Hence me thinking it was probably the alt. regulator. I have cleaned up the earths that I have found, but didnt know of one under the battery box. I will do all the checks as you say asap, but in the meantime my son has bought a Diag. tester which should be here thursday. It is a Blue Driver. So I will report back soon hopefully.
Peter.

Pete C wrote: ↑Wed Nov 11, 2020 9:29 pm HI , thank you for the suggestions, I will try what you have stated. Just as a recap, before the alternator was changed I tested the output at the battery and it was around 14 volts. Also I plugged in one of those cheapy alternator testers ( Lidl,s finest ) and it showed up the voltage surge as the lights flickered. Hence me thinking it was probably the alt. regulator. I have cleaned up the earths that I have found, but didnt know of one under the battery box. I will do all the checks as you say asap, but in the meantime my son has bought a Diag. tester which should be here thursday. It is a Blue Driver. So I will report back soon hopefully.
Peter.

The voltage surged? Did the voltage go up or down (from the nominal 14V)?

Typically the negative of the battery goes to the gearbox and the the chassis as one continuous piece of cable. I would check all three connections (battery, gearbox, chassis). You will need to remove the air filter box to get a good look at the gearbox connection and as Arfur said the chassis connection is under the battery box (if I remember correctly). Either way you can follow the cable from the negative terminal of the battery. The positive is one long cable from the alternator to the starter then to the battery then to the BSM (the fuse box in the engine bay). It's unlikely to be the positive because of that short run from the battery positive to the BSM....oooh hang on! If the positive connection at the BSM is loose that might cause trouble. Remove the cover to the engine bay fuse box and check the nut on the stud of the termination of the cable to the battery positive terminal. WARNING that terminal is connected directly to the battery positive, do not touch exposed chassis components with tools!!

If the battery is OK the system voltage shouldn't dip below (about) 12 volts (at worst) if the alternator stopped working intermittently...not enough to cause engine trouble and relays to drop out. You might see the headlights brightness change slightly. The whole systems voltage would only be changing by 2 volts. If the battery was a problem it would be difficult to start the car.

Why did you have a new alternator fitted? To attempt to fix this problem? Or something else?

Thanks for your reply. When checking the voltage at the battery it jumps momentarily to about 15volts for a split second occasionaly which is when the lights flicker. The alternater was fitted as I thought that its regulator was the problem.
I will check those earths as soon as possible.
Thanks for the input chaps.

Sorry, I edited my post above while you were posting. Have another read.

Check the nut on the stud on the BSM from the battery positive.

If the voltage is jumping up but the lights are dimming that indicates that the load is dropping off the alternator. Lost +ve or -ve connection.

If the voltage is jumping up and the lights are going brighter that indicates that the regulator is not working correctly.

Thanks OZVTR,
I have cleaned the earth connections as you advised, however I must have missed the one you posted with a picture. I will have a look at that also. The flickering is still there at the moment. As I said in an earlier post, we have been looking at the Blue Reader code reader. The write ups seemed good so we invested in one. I was amazed at how much info it produced. However nothing as yet found on charge rates or alternator/battery. May be we havent found it yet. It did show one item though, a suspect crank sensor. When driving the car and just ticking over, the timing advance was all over the place. Even when ticking over I would have thought it would be fairly stable. Obviously the advance changes due to engine load etc, but not by 30 deg. or more? Anyway we fitted a new one today, but only tried it ticking over due to other pressing matters, and it varied only by about 3 or 4 deg. I checked the ohms on the new before fitting and it was440. WhenI checked the old one the reading wasnt stable at all so I couldnt really tell. I tried it with both meters, analogue and digital, digital was best to read though.
My next step is to check the items you mentioned re the BSM.
Thanks again for the advice, Peter.

Check the terminal indicated by the arrow. CAUTION if the battery is connected this terminal is battery +ve. Do not let tools contact this terminal and the chassis at the same time!!

Pete C wrote: ↑Sat Nov 14, 2020 9:18 pm Thanks OZVTR,
I have cleaned the earth connections as you advised, however I must have missed the one you posted with a picture. I will have a look at that also. The flickering is still there at the moment. As I said in an earlier post, we have been looking at the Blue Reader code reader. The write ups seemed good so we invested in one. I was amazed at how much info it produced. However nothing as yet found on charge rates or alternator/battery. May be we havent found it yet. It did show one item though, a suspect crank sensor. When driving the car and just ticking over, the timing advance was all over the place. Even when ticking over I would have thought it would be fairly stable. Obviously the advance changes due to engine load etc, but not by 30 deg. or more? Anyway we fitted a new one today, but only tried it ticking over due to other pressing matters, and it varied only by about 3 or 4 deg. I checked the ohms on the new before fitting and it was440. WhenI checked the old one the reading wasnt stable at all so I couldnt really tell. I tried it with both meters, analogue and digital, digital was best to read though.
My next step is to check the items you mentioned re the BSM.
Thanks again for the advice, Peter.

Hmm, was the idle rough? Did you notice anything out of the ordinary with the performance of the car, before changing the sensor? Did changing the crank angle sensor make any (noticeable) difference to the performance of the car? Was the engine light on?