Replace Alternator

[leodevil]

Hi,

I wanna know if anyone could help me how to replace a alternator in a 120d..(code motor is N47D)
I have removed the two bolts but it doesn't get out..

Cumps...

[kamilS]

gahhh couldnt find a n47d but im sure n47 is same set up

http://realoem.com/bmw/diagrams/m/g/232.png

just two bolts. yank on it, should come off. twisting it sideways helps as well

[leodevil]

thanks, i removed the two bolts, but the alternator is still stuck, i dont know if is really necessary to loose to belt or if it will jump off with only these two bolts removed..

[Dackelone]

Originally Posted by leodevil

thanks, i removed the two bolts, but the alternator is still stuck, i dont know if is really necessary to loose to belt or if it will jump off with only these two bolts removed..

What makes you think the alternator is bad? Besides the code>? Maybe its a loose wire or bad rectifier or even a bad battery? Have you ever replaced your battery (Did you also have it coded to the car? You must code it!!).

You can use a VOM (Volt Ohm Meter) and measure the DC voltage across the battery terminals. The battery should have ATLEAST 12.8 volts with the car off. With the car on(engine running) you should have at least 13.5 DC volts at the battery.

With the engine running check for AC voltage... you should not have more than 1 ACvolt across the battery.

And IF your VOM has a peak/hold mode... (or you have a helper) measure DCvolts from the ground at the battery to the engine ground - they start the engine. IF you have more than 1 DCvolt... when you start the engine... you have a bad ground somewhere.


Changing the Alternator...

First DISCONNECT the battery before working on the Alternator. I have seen guys cause firs by forgetting to disconnect the battery! Look at RealOEM.com it looks like there are only two bolts. But you will have to remove the polly ribbed drive belt - to remove the alternator. I have never done it on a 1er but this aint rocket science. lol

Here are some pics to help you out. Perhaps have a BIG pry bar handy to pry the old atlernator out of its bracket that is bolted to the engine.

Good Luck
Dackel

[leodevil]

Thanks..
I measured at the terminals of the battery for AC voltage with a standard VOM and showed 26V at idle and 32 V with the engine running.. Is the alternator isn't??