Electrical black out

[rapidel]

Happy new year for you smart guies.
The beginning of the year is a bit cloudy for me and my 525i from 1990.
These last days the auxiliairy power supply seems to switch off all alone randomly.
The practical effect is the following: the radio resets, the wipers stops
and not the least the doors IR remote control lock/unlock system is not
operative. Fortunately when this happens the motors still works fine.
The first time it happenned, was three months ago. Now it is almost
once a day !

What could it be ?

Thank you in advance for your kind answer. :(

[shogun]

Electric black out means it is dead. But that is not the case. You just have a little bit trouble.

So what have you checked since it happened first time 3 months ago?
Any data available from first time of your checking?

Have you checked the basic stuff:
battery voltage, battery voltage when charging, battery voltage at idle or when engine is running at ? RPM?

Do you have any warning signals in the check control (if you have that) ?

Did you install anything new and connected it to the power supply somewhere?
details?

So, as you can see, a little bit more info fromyou would be helpful, to help you

[Dan in NZ]

Sounds like a fusible link going bad to me... Since you don't state the year or model of your car, there are two scenarios:

Battery under back seat: 1 fusible link in a small black box in-line with a the thick cable coming from the battery

Battery in engine compartment: 1 Fusible link near battery, and 1 fusible link under the back seat on the right hand side.

The fusible links cost about 50 cents, and are easily replaced. Make sure you use one with the same ampere rating as the old one. This is a common problem and has been addressed many times, for pictures and more infor check www.bmwe34.net

[rapidel]

Hi

Thank you for your replies. I will check these damn fuses and fuse holders.
The battery is close to the engine. The reference of the car is HD61080.
525i with M50 engine, GM automatic gear box and automatic A/C system.
Very few models of this type were produced in year 90.
Mileage: 242 000.

[shogun]

Used what you indicated on the online catalog, but does not work apparently.
Check that again.
here is the link (http://www.realoem.com/bmw/select.do?vin=HD61080&kind=P&arch=0)

[rapidel]

Used what you indicated on the online catalog, but does not work apparently.
Check that again.
here is the link (http://www.realoem.com/bmw/select.do?vin=HD61080&kind=P&arch=0)
The fuse was actually out of order. But this was not visible. Attached you
will see the old vs a new one.
My car's references are correct and are engraved on a shee-iron at the rear of the motor compartment.
Who is able to tell me the life expectancy of the alternator's brushes, this begins to scare me as the time elapses.

Thank you in advance.