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Discussion Starter · #1 ·
HI,

I am after a bit of advice from anyone who may shed some light on my issue.

I have a UK 2009 Focus TDI

IN the the last weeks i have had my dipped headlight beams blow (both at the same time) All other lights are working fine.

The first time just thought it was unlucky that both blew, a week later after being replaced with a pair of brand new osram branded bulbs which cost me £20 they both blew agian.

I have just replaced them a 3rd time now and will see how i get on but i just feel that something is not quuite right.. anyone has any ideas?

Thanks in advance
 

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2004 Focus Wagon, Zetec DOHC, Auto
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It is quite possible that your alternator is failing and causing high voltage.

Put your odometer into diagnostic mode and watch the voltage as you drive the car. The car may show higher voltage right after it is started as the smart charge system does its thing, so ignore that. Anything over 15 volts while you are driving is not good on bulbs.
 

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It is quite possible that your alternator is failing and causing high voltage.

Put your odometer into diagnostic mode and watch the voltage as you drive the car. The car may show higher voltage right after it is started as the smart charge system does its thing, so ignore that. Anything over 15 volts while you are driving is not good on bulbs.
Hey FocusKnot. I had a similar problem a little over a month ago as the OP. I don't mean to thread jack. Sorry. Driving and check engine light came on. Soon after, both headlights blew at exact same time. Replaced lights, fixed code and nothing new has happened (knock on wood). Anywho, I did as you suggested on my way into work this morning. As I drove, the voltage would range anywhere from 14.3-14.9V. Never higher. Fluctuated between there.

Now with my flickering lights issue, I was hoping this would help shed some light (no pun intended) on the matter. Would the fact that it is so close to the 15V mark tell you something? Or is this normal?

I am currently looking into DIY Alternator rebuild as I want to learn how to do it anyways. It is next on my list of To-Do's.

thanks.
 

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^^^ The 14.3-14.9 volt fluctuation would be normal IMHO. Not likely to cause any noticeable flickering of headlights. That would be due to a wiring issue most likely and could be battery cables or wiring at headlights. The other thing to check is the 3-wire connector on the alternator.
 

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^^^ The 14.3-14.9 volt fluctuation would be normal IMHO. Not likely to cause any noticeable flickering of headlights. That would be due to a wiring issue most likely and could be battery cables or wiring at headlights. The other thing to check is the 3-wire connector on the alternator.
Yeah, I've already cleaned my grounds and soldered in the new pigtail. Only thing left is to install new battery cables. Sucky weather narrows down the opportunities to do so. Thanks for the reply FocusKnot!
 

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Just to be clear on terminology, I consider flickering to a sudden On-Off condition which is usually wiring related. A loose connection or a wire shorting out with vibration are examples.

If the lights are pulsing, as in getting dim and then brighter, then that could be alternator related. I had that happen with my alternator and it only showed up after the alternator warmed up. It even bench tested okay. Apparently the regulator had a heat issue.
 

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Just to be clear on terminology, I consider flickering to a sudden On-Off condition which is usually wiring related. A loose connection or a wire shorting out with vibration are examples.

If the lights are pulsing, as in getting dim and then brighter, then that could be alternator related. I had that happen with my alternator and it only showed up after the alternator warmed up. It even bench tested okay. Apparently the regulator had a heat issue.
Good catch. You are correct in your definitions. This is not a "flickering" from on to off. This is the constant dimming of the headlights. At times, it appears more significant. This also occurs within the dome. The flickering has no rhyme or reason and is obviously more apparent with the LED's I have (both interior and in the back).

This was doing it when I had replaced my alternator (purchased from Autozone) five years into owning the car back in 2012. I even created a thread then about it as I had just replaced the alt. But after reading numerous threads here, I'm now more comfortable with the fact that it was just a crappy alt from the beginning, now getting even crappier. Which is also why I'm either trying to rebuild one myself or have a shop do it.

Thanks again and sorry to thread jack.
 

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If the lights are pulsing, go straight for the alternator or the 3-wire alt connector (which in your case you have already replaced).

I am on my third Autozone rebuilt in about 2 years. The other two had pulsing problems. The first one did it when I would start the car. After a few minutes the pulsing would stop. The second alt developed the heat problem after a few months and began pulsing while driving. The third alt seems to be the charm so far.

If this third one craps out, I will probably just rebuild it instead of doing yet another warranty exchange.
 

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Sounds good. Exactly like my issue I've been experiencing. It only makes sense that it is getting worse over time. I'm hell-bent now on having a rebuild installed and not going through the major chains for one. Plus it is a good learning experience to rebuild it. :)
 
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