Flickering head/interior lights

[STEVE36]

What causes it?

114k on my current alternator (Valeo).

Need ideas here.

Steve

[STEVE36]

The problem seems to have worsened recently. My car starts fine, every time. This is not likely a battery issue, correct?

Steve

[HDIDDY]

Your voltage regulator is probably starting to die on you.

[Green318is]

I had the same issue. I first replaced the battery but it did not solve the problem. I then removed the alternator and replaced the voltage regulator (cheap - $35). However, I am almost sure that the problem was caused by a bad alternator ground wire. It was badly corroded. It's difficult to check because it's located in the back of the alternator.

[SQ Bimmer]

This may seem retarded, but tighten down your battery terminals.

[heifetz17]

I doubt it's a battery/alternator issue as you would then experience problems with other electronics in the car. Check the wiring for the lights. Maybe there's a damaged wire somewhere?

[STEVE36]

Can you guys give me some more information on the voltage regulator?

Is that $35 at the dealer? Where is it located? What's it's function?

Steve

[derek9702]

I had the same problem. It turned out it was the voltage regulator. I went ahead and replaced the alternator. I figured while it was out, might as well replace it.

[STEVE36]

I had the same problem. It turned out it was the voltage regulator. I went ahead and replaced the alternator. I figured while it was out, might as well replace it.

Easy job? I need more info on the voltage regulator if ya have it! :)

[98dinan3]

same light problems as you, also a surging idle. both solved by replacing the alternator.

[STEVE36]

I grew up right by Hamilton.

Did you go for the 140 Bosch or what? Approximate cost in USD?

Steve

[STEVE36]

I doubt it's a battery/alternator issue as you would then experience problems with other electronics in the car. Check the wiring for the lights. Maybe there's a damaged wire somewhere?

Actually the cluster lights seem to dim very intermittantly and only for a second. I've actually never pulled my alternator before. A good time to check out my belt tensioner issue as well?

[antonk]

I've got the same problem with flickering headlights/interior lights and slight idle bounce (don't know if that's the right term, but it goes up and down a little). My assumption (and hope) is that it's the voltage regulator, because as far as I remember when I had the voltage checked a few months ago, it went anywhere between 12 and 14 volts, and flickering lights are often caused by bad voltage regulators. I'm taking it into the local BMW specialist tomorrow to diagnose the problem, and I'll let you know what they say... if I remember. I might be too excited about a cheap fix, or too depressed about having to get a new alternator.

[98dinan3]

where'd you grow up?

[STEVE36]

I've got the same problem with flickering headlights/interior lights and slight idle bounce (don't know if that's the right term, but it goes up and down a little). My assumption (and hope) is that it's the voltage regulator, because as far as I remember when I had the voltage checked a few months ago, it went anywhere between 12 and 14 volts, and flickering lights are often caused by bad voltage regulators. I'm taking it into the local BMW specialist tomorrow to diagnose the problem, and I'll let you know what they say... if I remember. I might be too excited about a cheap fix, or too depressed about having to get a new alternator.

Please post what you hear tomorrow, to help us other guys out too.


where'd you grow up?

Born in Toronto. Grew up in Oakville, mostly.

[98dinan3]

drove through oakville tonight...coincidental

[Mminehan]

Also, might pay to check the wiring to the trunk. There's a thread about worn wires in the rubber shroud that connects the trunk to the body, near the hinge. People have reported lights dimming, and even fried wiring looms etc.

Just a thought.

[SergeK]

bump, same problem here. Flickering lights, jumpy idle, cluster sometimes dims. AC Display dims.

[Green318is]

I removed the alternator and replaced the voltage regulator, the alternator's ground wire and the belt. I am sure that it's easier to do it in the 318is because of the additional space you have in the engine bay. I don't have a lot of experience and was able to do it without help. Just get a Bentley manual, it will guide you through the whole process. It took me about 1 hour to do it. Easy and fun DIY.

[STEVE36]

Also, might pay to check the wiring to the trunk. There's a thread about worn wires in the rubber shroud that connects the trunk to the body, near the hinge. People have reported lights dimming, and even fried wiring looms etc.

Just a thought.

Yeah I've already looked into the trunk wiring problem.

[SergeK]

Kind of offtopic, but Steve36m what kind of exhaust is that in yer pic?

[TC535i]

Another vote for the alternator. Assuming the belt is tight (can't turn it 180 degrees by hand) and it's not slipping/squealing, the fact that it's getting worse points even more to the alternator. Check the output charging voltage, my bet is you're not getting the 14+ volts you should be. Replace it before it leaves you stranded...

[s0rserer]

same problem here, waiting for response from bmw professional...subscribed

[STEVE36]

Another vote for the alternator. Assuming the belt is tight (can't turn it 180 degrees by hand) and it's not slipping/squealing, the fact that it's getting worse points even more to the alternator. Check the output charging voltage, my bet is you're not getting the 14+ volts you should be. Replace it before it leaves you stranded...

It may just seem like it's getting worse. I'm not throwing out that it may be the alternator though.

The exhaust is Scorpion. I have a review if you wanna search. Good exhaust for the money, but I'd recommend spending more.

Steve

[TC535i]

Check the charging voltage. That'll tell the story...

[antonk]

So I'm back from the shop... I showed up a little early, and while every mechanic was on lunch I took a look at my own battery to check for wiring problems - looks brand new. So I decided to save money by not having them check the voltage, as I had already done that before, and it was going up and down. So just by talking to the mechanic we figured that it's most likely the voltage regulator, which happens to be internal in my Valeo alternator. You basically have to take it apart to replace the regulator, so you might as well have the whole thing rebuilt, since other parts of it might be worn as well (mine's still original from 92).
The place they use to rebuild alternators can't tell me a price until they take it apart, but they're saying at least $200 CAD (close to $180 US), plus an hour of labour to take it out and put it back in.
Not knowing the price until AFTER they've already taken it apart makes me kinda nervous, so I'm gonna phone around to see if I can get a cheap new one, or just do nothing and watch the lights flicker and bulbs burn out once in a while, hoping my ECU doesn't get fried.
Basically my advice is that if you can do the work yourself, just buy the voltage regulator and replace it yourself (if it's easy in your alternator), cause that should only cost like $35. Or if you've got the money, just have the entire alternator rebuilt so that you don't have to worry about it.

[STEVE36]

Cool. I am going to have my voltage regulator checked out.

[s0rserer]

i know my alternator was going in between 14.5 and 15.5 volts. so i probably have the voltage regulator problem as well but i found someone that sells rebuilt alternators around here. He said hell install one for me for 165 as long as he can take my old one.

Anyone in the area if you need the info let me know

[STEVE36]

How can I test the voltage regulator (myself) without the nice OBC?

[TC535i]

How can I test the voltage regulator (myself) without the nice OBC?

Measure output from the alternator? :dunno

[antonk]

Yeah, I don't think you can test the voltage regulator per se. You kinda have to guess and assume that it's the problem. I found a friend who's willing to do the replacement for me since he's done it before and says it's an easy job. So we'll just replace the voltage regulator and maybe the brushes, and that should do the trick for about $50 or so.

[antonk]

BIG UPDATE!!!

I just got my problem fixed! It cost me CAD $60 including parts and labour, and I did none of the work myself! I have the 105A Valeo alternator, which contains the voltage regulator inside a plastic cover on the back of the alternator. My mechanic took off the alternator, opened the back cover and replaced the voltage regulator (which cost me all of CAD $25). Looking at the old regulator it became very obvious that that was the problem behind my voltage irregularities, because the two brushes were worn unevenly, so there is no way contact was being made with both of them properly. The $60 also included a new alternator belt, since mine was cracking. Now there is no flicker, and my idle is much better with no bounce whatsoever.

So if you can manage to pull out the alternator yourself, spend the $30 or whatever it costs you on a new regulator and install it yourself. It already comes with the brushes and everything. Looks like that will fix most flickering problems, and will cost you next to nothing if you can do the labour yourself (which is very easy anyway, especially once you get the alternator out).

My only regret is not getting this fixed a year ago when I bought the car, because I spent almost as much money on burning out lightbulbs and probably slightly decreased fuel economy due to an irregular idle.

So if your alternator charges fine but voltage fluctuates, don't bother rebuilding it or buying a new one. Start with the regulator and see where it takes you!

Hope this was helpful!

P.S. To clarify exactly what my problem was to make sure yours is the same: Headlights and interior lights flickered all the time, pretty much to the same degree. Quite often when stopped at a red light, the idle would go up as much as ~200 rpms and dip back down, which was very annoying. My alternator seems to be original from 92, and it's the 105 Amp Valeo which contains the voltage regulator inside a plastic housing, which you can't get to without taking the alternator off (even on a 318 which has more room under the hood). New regulator should cost about $30 and includes everything you need. You may also consider replacing the belt(s) as you do this.

[STEVE36]

Doesn't sound expensive at all. Cool.

[s0rserer]

so based on the major update i took my car to the mechanic and he said that the vr was soldered in or some bs like that. i know the bunghole is just too lazy to do it so ima have to find an alternator specialty shop to get er done. thanks again for the info though.

[Kipp@Modtech]

my car has been doing this for about a year. I always suspected the voltage regulator to be the problem. When I posted about it no one really said anything but apparently it is a common problem. Now I know. thanks d00dz. :eek:

[e36]

i have this problem now...i almost shit my pants wen it first happened...(i almost bought a fire extinguisher)

[westcp]

BIG UPDATE!!!

I just got my problem fixed! It cost me CAD $60 including parts and labour, and I did none of the work myself! I have the 105A Valeo alternator, which contains the voltage regulator inside a plastic cover on the back of the alternator. My mechanic took off the alternator, opened the back cover and replaced the voltage regulator (which cost me all of CAD $25). Looking at the old regulator it became very obvious that that was the problem behind my voltage irregularities, because the two brushes were worn unevenly, so there is no way contact was being made with both of them properly. The $60 also included a new alternator belt, since mine was cracking. Now there is no flicker, and my idle is much better with no bounce whatsoever.

So if you can manage to pull out the alternator yourself, spend the $30 or whatever it costs you on a new regulator and install it yourself. It already comes with the brushes and everything. Looks like that will fix most flickering problems, and will cost you next to nothing if you can do the labour yourself (which is very easy anyway, especially once you get the alternator out).

My only regret is not getting this fixed a year ago when I bought the car, because I spent almost as much money on burning out lightbulbs and probably slightly decreased fuel economy due to an irregular idle.

So if your alternator charges fine but voltage fluctuates, don't bother rebuilding it or buying a new one. Start with the regulator and see where it takes you!

Hope this was helpful!

P.S. To clarify exactly what my problem was to make sure yours is the same: Headlights and interior lights flickered all the time, pretty much to the same degree. Quite often when stopped at a red light, the idle would go up as much as ~200 rpms and dip back down, which was very annoying. My alternator seems to be original from 92, and it's the 105 Amp Valeo which contains the voltage regulator inside a plastic housing, which you can't get to without taking the alternator off (even on a 318 which has more room under the hood). New regulator should cost about $30 and includes everything you need. You may also consider replacing the belt(s) as you do this.


hey where did you get the part from? not many places in kelowna have parts for bmws.

[antonk]

I got the part at Lordco, which there are 2 of in Kelowna. List price should be $35 (I get dealer discount, so it cost me $25). I believe even Canadian Tire will have the voltage regulator, since it doesn't seem to have to be a BMW part.

[STEVE36]

Just an update - normally alternators crap out all at once. Mine was on a slow decline for some reason. It's being replaced.

Going with the 140amp one to be safe.

Steve

[s0rserer]

ok so i changed my alternator over the weekend and now the flicker is not nearly as bad but its still there!! any other ideas?

[e36]

voltage regulator"?

[nspirin]

First and foremost great info and taking th etime to share it with us. I just recently bought a 1998 323is and now all of my interior lighting is not working. So could this be the problem? And if so how do i check it? Any feedback would be greatly appreciated before i run to the stealership to get this fixed. Oh and when i say none of the interior lights work i mean the guages and all of the ac and shifter lights are all completely OUT! But the radio lights, obc, ac display, blinkers, etc. all are working it's just everything that's supposed to be illuminated isn't working??? Completely stumped.

[antonk]

I wouldn't think this would have anything at all to do with the alternator. Maybe fuses or cables somewhere, but I don't really know.

[s0rserer]

First and foremost great info and taking th etime to share it with us. I just recently bought a 1998 323is and now all of my interior lighting is not working. So could this be the problem? And if so how do i check it? Any feedback would be greatly appreciated before i run to the stealership to get this fixed. Oh and when i say none of the interior lights work i mean the guages and all of the ac and shifter lights are all completely OUT! But the radio lights, obc, ac display, blinkers, etc. all are working it's just everything that's supposed to be illuminated isn't working??? Completely stumped.

fuses for sure

[nspirin]

But i've checked and re-checked all of my fuses three times. I even had my dad check all of the fuses and they are all good? Completely stumped?!! Still. Someone please give me ideas...

[STEVE36]

I wouldn't think this would have anything at all to do with the alternator. Maybe fuses or cables somewhere, but I don't really know.

Well, I just described the symptoms. And the solution, which was the alternator. So...

nspirin - If you are getting NO power, then I don't know what to tell you. It could be alternator related. Take it to an independent service shop for lower prices to diagnose your problem.

[antonk]

Well, I just described the symptoms. And the solution, which was the alternator. So...

I thought your problem was flickering lights, not NO interior lights... My comment about it not being alternator related referred to the no lights problem.

[RJ 325is]

My interior lights(dome and rear interior lights)turn on and off sometimes, or it briefly illuminates dimly then fades back out or stays on dim while I'm driving. Is this the voltage regulator that's causing the problem? :help

[e36]

Check your door hinge.

There is like a small button where the door actually latches which tells the car whether the door is open or closed.

Do your locks go haywire sometimes?

-mike

[RJ 325is]

Check your door hinge.

There is like a small button where the door actually latches which tells the car whether the door is open or closed.

Do your locks go haywire sometimes?

-mike

W
The button/s inside the door :dunno. No my locks are fine.

[RJ 325is]

I'm not having problems with my idle surging just the interior dome and rear lights going on and off intermittently, or slowly fading on and off or sometimes just light fade while I'm driving. I checked the buttons on the door jambs thinking they might get stuck, but they seem fine:dunno

[youngGun328]

is the voltage reg. part of my alternator or a seperate component? I have the flickering problem and I just replaced the whole alternator. ('96 328is)

[e36]

the flickering is cause by faulty door hinges. open ur door and ull see on the chassiss the hinge there is a button in it. press it and you'll see lights go on and off

[s0rserer]

is the voltage reg. part of my alternator or a seperate component? I have the flickering problem and I just replaced the whole alternator. ('96 328is)

its usually inside the alternator or a little unit sticking out the back. either way if they replaced your entire alternator it should have been replaced with it (unless its a shady shop or something)

[youngGun328]

I replaced the alt. myself. I ordered a complete one from a local parts shop and then did it in my garage so maybe I had to order that part seperately?

[Davebmw]

Its the valeo alternator that is the problem the brushes and slip rings have worn and the charge regulation has become erratic. if you had a Bosch you could replace the regulator module and the problem would go away. but with the valeo French crap alternator you need a new or recond unit.
i'm not sure if you can directly replace a valeo unit with a bosch but if you can for gods sake do it and make sure you make some sort of dust filter to put in the cooling duct this will save loads of wear due to dust and grit.

[DeadMeat]

Hi guys, is this problem running through to the E46's ?, i have the idle bounce but not so much light flicker do you think this could still be the voltage regulator ?