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Discussion Starter #1
So took the family to the beach for spring break. Car ran fine and then battery light came on. Menu test shows 11.1v standing and 11.3 running and battery window is now black. Waiting on a friend to show up with multi meter, but if the alternator was working, wouldn't it show more than 11.3 v on the menu test?

Assuming this is the alternator that needs to be replaced a couple questions on the posted DIY:

- I have access under the car, but limited. If I can get the belt off and the bolts undone do I really need to take off the power steering pulley?
- Do I also need to remove the fan if I take the alternator out the bottom?
- Is it possible to take the power steering pump off its mount to make room to remove the alternator or is taking the pulley off the only route?

This sucks, but 100 miles from nearest dealer and nobody down here has the part so will have one overnighted.

Any pointers appreciated.
 

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If the voltage stays low then the alternator isn't working, either it is broken or there is a broken wiring connection somewhere.

I can't help on the other questions :(




PLEASE NOTE THAT I DO NOT OWN AN M5 AND THIS POST IS NOT INTENDED TO BE ARROGANT. PLEASE READ THE IMPORTANT

REVISED DISCLAIMER THAT APPLIES TO

THIS POST
 

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Check the connections on the back of the alt before removing (not sure if that is practical on this engine). Also could be as simple as swapping in a new set of brushes/regulator, but I really don't know if that is possible on your alternator either. You'll have to look and see what is serviceable from your current location.
 

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- I have access under the car, but limited. If I can get the belt off and the bolts undone do I really need to take off the power steering pulley?
No, you need to remove the pump.
- Do I also need to remove the fan if I take the alternator out the bottom?
Edit: I am not sure about the fan, I forget I'm not running the stock fan. I think you could do it without it though.. (I have never heard of needing to take the fan off. I never have. )
- Is it possible to take the power steering pump off its mount to make room to remove the alternator or is taking the pulley off the only route?
This is what you need to do. I wouldn't recommend trying to remove the pulley, they are fragile and it will probably break on you.


Which DIY are you looking at?? Try this: http://m5alternator.blogspot.com/
 

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Discussion Starter #5
Perfect that DIY looks like what I need

Much appreciated, will post how this goes...now I gotta find some makeshift ramps.
 

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disconnect the neg lead on your battery then pull the fan remove drive belt and may be the belt tensioner un bolt the alternator and arefully slide it out of her hole its not hard
 

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Discussion Starter #9
Progress Update

Thanks for the link to that DIY Frye, that is definitely the way to go. Splurged on some crap tools and a $18 jack from walmart, got the front up on some scrap wood. A couple quick observations:

- Borrowed a multimeter. Car was 11.9v standing, 11.2 running. Tested for continuity from the front battery terminal to the actual battery (with negative cable off). Checked out so certainly seems like the alternator is to blame (fingers crossed).

- No need to remove fan if you go from under the car. Once you get the dust cap off that pulley the T50 torx on a 3/8 ratchet will definitely fit.
- Remove 3 bolts on power steering pump per DIY and pull to the side, hang with some kite string (all I had at the beach).
- Was impossible to reach the connectors on the back of the alternator while on its bracket so removed two bolts and then removed connectors (one has that little sliver spring clip you have to move forward and then plug slides off.
- The 17mm ratcheting wrench would have saved much time but didn't have one. Was able to get a regular socket on there and work away.
- The pumpkin then simply drops down.

Hardest part of this is holding the stupid thing up there with one hand while trying to get wrenches on stuff with the other.

Now I hope the replacement shows up in time to put in and that solves the issue. Ugh.
 

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Discussion Starter #11
Progress Update

Got the new alternator overnighted from ECS and arrived at the beach around 5:00. Took about an hour to get the new one in. Hardest part was getting the cable attached to the back. I ended up holding the alternator while my wife with her small hands was able to get the thread started.

14.2v running and 12.9 standing so definitely was the alternator. Not sure when it decided to blow, no warning signs that I can think of. Thanks for the links to the DIY. Not particularly hard, but a little stressful without the proper tools and 400 miles from home. Live and learn.
 

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Got the new alternator overnighted from ECS and arrived at the beach around 5:00. Took about an hour to get the new one in. Hardest part was getting the cable attached to the back. I ended up holding the alternator while my wife with her small hands was able to get the thread started.

14.2v running and 12.9 standing so definitely was the alternator. Not sure when it decided to blow, no warning signs that I can think of. Thanks for the links to the DIY. Not particularly hard, but a little stressful without the proper tools and 400 miles from home. Live and learn.

Way to go.:cheers:

One of the better feelings of accomplishment in this life, eh?
 

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I am in the DC area too and this just happened last week. What tests did you do to make sure that it was the alternator? I've done the #9 on the menu already and it's got similar numbers to you. Any suggestions would be appreciated.
 

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In all seriousness, this board and its members have probably saved me $3k in fleecing for repairs over the years so thanks to everybody who makes this place special. Now time to enjoy the hot tub and a scotch. :cheers:
Nice. It's this board and all the helpful information here, including the DIY thread, that has made owning this car reasonably inexpensive, lol. Such a great resource here. In fact, I just did my alternator using that DIY not too long ago. I didnt pull the fan either but was tricky getting the belt loosened with such tight spacing. Luckily I have small hands so was able to get everything else pretty easily. I also dropped the PS pump completely.

Great feeling of accomplishment getting something like that done. Cheers!
 

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Discussion Starter #16
Couple ways to check

Sorry, just logged back on for first time in a week. To check the alternator I did the following:

1. The menu test with car running was showing 11.0-11.1 and didn't vary at all with engine RPM.
2. I took a multi meter set to the voltage level. Put leads directly on battery with car off and got maybe 11.6-11.9v.
3. Started car and again put multi meter on battery. Showed 11.0-11.1 volts running and no fluctuation.

The battery should show over 12 volts standing and 13.5 or better running to show the alternator is charging. Mine fluctuates between 13.6-13.9 when it is running.

4. To make sure the lead from the battery to the alternator was good, I tested the jumper lead i the engine (under that cover with the +) on it with the multi meter between that terminal and a bare metal part on the car. Was 11.6 standing and no change running. That at least eliminated the risk that the cable was broken or some fuse someplace was dead.

End result was once I put the new one in it runs fine and charges perfectly If you get stuck swapping it out shoot me a note and I'll tell you what I did if it helps.
 

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Curious - how many miles on the car?
 

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Sorry, just logged back on for first time in a week. To check the alternator I did the following:

1. The menu test with car running was showing 11.0-11.1 and didn't vary at all with engine RPM.
2. I took a multi meter set to the voltage level. Put leads directly on battery with car off and got maybe 11.6-11.9v.
3. Started car and again put multi meter on battery. Showed 11.0-11.1 volts running and no fluctuation.

The battery should show over 12 volts standing and 13.5 or better running to show the alternator is charging. Mine fluctuates between 13.6-13.9 when it is running.

4. To make sure the lead from the battery to the alternator was good, I tested the jumper lead i the engine (under that cover with the +) on it with the multi meter between that terminal and a bare metal part on the car. Was 11.6 standing and no change running. That at least eliminated the risk that the cable was broken or some fuse someplace was dead.

End result was once I put the new one in it runs fine and charges perfectly If you get stuck swapping it out shoot me a note and I'll tell you what I did if it helps.
Thanks for the note. I just got mine in the mail and will give it a go. Is it possible to do this procedure without going underneath/using jack stands?
 

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Discussion Starter #19
I couldn't find a DIY from the top, but...

I suppose it would be possible, but you'd have to remove the fan, and probably the drivers side airbox and intake to get enough room to pull it. Hardest part would be getting the bolt that holds the wire on the back of the alternator off IMO. There is very little clearance.

I'd borrow some ramps or jack stands and tackle it from the underside. I did it with a crappy walmart jack on one side to give a little extra clearance since my car is lowered a bit. Follow the DIY at the begining of the thread and you can't go wrong. Just remember, this thing weighs like 18-19 lbs so having a helper who can hold it while you get the nut started on the cable terminal will come in hand.

Good luck.

P.S. I've also used a driveway apron to drive two wheels up on a curb and then laid down in the gutter to get underneath. Looks a little gehtto but works just fine.
 

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It would be more ghetto to attempt this in my apartment parking garage. Thank you for the tips, I will make the necessary arrangements to get it to a more suitable working space.
 
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