Question on Alternator Replacement

My tachometer comes on and off sometimes. I changed the original battery, but the tach still doesn´t work sometimes. I have light on the cluster but no revs and no power... when i am driving simply starts like it was nothing.

The electrician told me that it was the alternator but i already test the voltage and it's good. Another important information is that this thing happens without starting the car key position 2, so the alternator is not running... the lights on the tachometer sometimes works and sometimes not... checked all the fuses and they are ok. They must be because that tach works 80% of the time. Another lights that are coming sometimes are the asc and the tyre pressure.

Can anyone help me? i don't know what to do more...

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This post was auto-generated based upon a question asked on our tech article page here: MINI Cooper Alternator Replacement (R50/R52/R53 2001-2006) | Pelican Parts DIY Maintenance Article

[Nick at Pelican Parts]

I would assume the tach is faulty. Using a MINI scan tool, check if RPM is available in data. If so, the tach is likely at fault. You may also have fault codes for tach communication.

- Nick