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  #1  
Old 06-28-2020, 01:28 AM
Foxxyguy Foxxyguy is offline
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Flickering passenger airbag light & Dome Light stays on?

2007 BMW Z4 3.0i. Basically as the title says. When I turn on my car, both my center console passenger airbag light has a seizure and my dome light randomly comes on and off randomly even when I make sure it's shut off. So there's the flickering and the random on and off cycles of my dome light ***x1f61e;

I replaced my alternator 6 months ago with a remanufactured one, so that may be my issue.

Maybe the voltage regulator is bad.

But I'm also thinking it could be a bad relay of sorts?

Anyone ever have this issue? It's not my battery because I swapped for a new one and no dice. Any thoughts?
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  #2  
Old 06-29-2020, 01:45 AM
Foxxyguy Foxxyguy is offline
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So i do notice the frequencies of the lights flickering and their brightness are directly affected by the speed of the alternator. When speeding up, they brighten before dimming down again, and when turning on/off other electrical components (A/C, wipers, etc) the lights are also affected.

This leads me to believe that it has to do with the alternators voltage regulator.

Surprisingly I still haven't gotten a battery light indicator. Maybe it's producing the correct voltage, and therefore no light, but the regulation of said current isn't correct, causing my lights flickering and other issues.

Taking my car into the auto shop to have the alternator tested, and if it's bad, then I'm bummed, but I know where the issue is.

Moral of the story : DONT BUY REBUILT ALTERNATORS ! They are usually repaired with cheap Chinese knockoff parts and if they barely work, then they'll sell them to you. Buy OEM or better
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Old 06-29-2020, 02:10 AM
Foxxyguy Foxxyguy is offline
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The only thing I would like to check before doing any buying of more parts, is I need to know the location of the Chassis Grounding point. This is where the negative cable connects to the chassis to make the frame grounded. I've looked online and didn't find much help. Please let me know if you know where it is located.
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Old 06-29-2020, 08:17 AM
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Clearancediver Clearancediver is offline
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The grounding strap can be either a solid cable or braided according to parts diagram. It doesn’t appear to be that long either. I’d look up in realoem.com for which one you have.

It’s been a couple of years or more since I had to roll around under the car.... but best time to look into the engine bay for the strap is in the evening with a high powered LED flashlight... you just get better visibility of the “hidden” areas. I would look first to the driver side where it’s more open to see anything attached to engine/body of car.


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Old 06-29-2020, 02:03 PM
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Clearancediver Clearancediver is offline
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Passenger side....

It attaches to the wheel fender where the ac pump is located.




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Old 07-02-2020, 04:21 PM
Foxxyguy Foxxyguy is offline
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Update: Ok! So I checked my grounding straps and they seem fine. The one on the passenger side engine bay is a little dirty, but it doesn't seem too bad. No fraying or damage that I could see.

Got alternator tested at O'Reillys because that's where I bought my rebuilt one. Bad diode. Replaced alternator with a new rebuilt one annnnnnd! Lights are still flickering. ***x1f61e;

I did notice a few more things going wrong too. My wipers don't work properly, going halfway and stopping, then 3/4ths and stopping etc. Both windows get suck rolling up and down, and when my alternator isn't spinning, the cluster lights flicker.

All of my headlights, indicators, etc work fine.

Is there a switchboard or something I could check out? I'm thinking maybe some water got somewhere it shouldn't, or maybe a bad connection between my electronic accessories and battery.

Any ideas are appreciated before I take my car into the stealers ***x1f61e;

Btw, no fault codes show up on my Foxwell 510.
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Old 07-02-2020, 06:14 PM
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Clearancediver Clearancediver is offline
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How can an alternator not spin? Do you mean that with ignition on and not started the dash lights flicker.

While you say you have a new battery, the alternator went bad in the meantime. I would have the battery checked for internal damage/bad cell etc.

Check the battery voltage in the morning when the battery is “cold”.... to start.

Take battery cables and use to ground engine to chassis.... to confirm it’s not a bad ground....

This is all to rule out an electrical fault.

Most of those hand held scanners really can’t read proprietary BMW codes and those that do are likely not reading them all. INPA and INSTA(D) software are worth purchasing if you really want to “read” codes and actual engine parameters while running.

I personally ( did for my car) would do the following....

I would disconnect both battery cables and then clean all the connectors you can reach. Don’t forget to clean the GM5 (?) box under the glove box. Bit of a bi..ch to get to but not too difficult.

Then.... if you still have the same issue... it’s dealer time.

My 2 cents worth...


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  #8  
Old 07-02-2020, 08:24 PM
Foxxyguy Foxxyguy is offline
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Quote:
Originally Posted by Clearancediver View Post
How can an alternator not spin? Do you mean that with ignition on and not started the dash lights flicker.

While you say you have a new battery, the alternator went bad in the meantime. I would have the battery checked for internal damage/bad cell etc.

Check the battery voltage in the morning when the battery is "cold".... to start.

Take battery cables and use to ground engine to chassis.... to confirm it's not a bad ground....

This is all to rule out an electrical fault.

Most of those hand held scanners really can't read proprietary BMW codes and those that do are likely not reading them all. INPA and INSTA(D) software are worth purchasing if you really want to "read" codes and actual engine parameters while running.

I personally ( did for my car) would do the following....

I would disconnect both battery cables and then clean all the connectors you can reach. Don't forget to clean the GM5 (?) box under the glove box. Bit of a bi..ch to get to but not too difficult.

Then.... if you still have the same issue... it's dealer time.

My 2 cents worth...


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Yes I meant when the ignition is on, but engine not turned over.

I did as you said, got to the box, cleaned the connectors even tho they're pristine, and cleaned my positive and negative terminals.

But to no avail.

But getting to the GM5 box gave me an idea. There's tons of wires going through the dash, and all of them connect somewhere. Genius analysis, I know. But they have to be grounded to something right?

Where would the grounding point be for my internal electronics?

Maybe a good clean there or tightening the connections down might be a possible fix.

Any ideas?
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  #9  
Old 07-02-2020, 08:27 PM
Foxxyguy Foxxyguy is offline
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Update: The ground for the internal electronics on the E46 is under the seat and carpet. Maybe it's the same here?Worth taking a look or should I give in to the BMW techs?
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  #10  
Old 07-03-2020, 10:13 AM
ZEEBOY ZEEBOY is offline
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These problems SEEM to me to be voltage related..buy a $3 voltage reader on ebay that plugs into your cigarette lighter...you should be registering high13 to low 14 volts under all driving conditions..
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  #11  
Old 07-07-2020, 09:53 PM
Foxxyguy Foxxyguy is offline
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Quote:
Originally Posted by ZEEBOY View Post
These problems SEEM to me to be voltage related..buy a $3 voltage reader on ebay that plugs into your cigarette lighter...you should be registering high13 to low 14 volts under all driving conditions..
Good idea actually. I'm gonna do that. If voltage isn't right, how could I go about fixing that? The only thing I could think about is wiring, alternator, bad grounds and bad battery.

I'll see what I can do and update here.
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