Would some kind sole please tell me what the value of the capacitor (I think) soldered between electrical terminals is.I was lubricating the fan and in the process I managed to break the the thing.  I am not an electrician but I think it to be a capacitor, possibly a starting cap.

Any numbers etc on it?

hard to read, but

B322?
067m100 (or 047m100)

not sure about that 4 or 6.

Can ya get a clear photo?

What shape is it?

I've done a quick search and can't find anything close to the numbers given.

A Google search definitely works with 047m100 in that it points in the direction of capacitors so it could be 47 microfarad and 100v trouble is there also appears to be .47 so at least it appears you are heading in the right direction.

Regards,

Phil

well done Phil, thank you. I can't believe that I didn't Google it first. now that i did and for your information this is what I've found:

"Yes, and capacitor that goes in parallel across the power supply
terminals of anything is called a bypass capacitor. The value....that's
really up to you. Try to pick a larger value since it will better
smooth *large* motor voltage spikes. Larger capacitor values also
filter out low frequency noise better.

The capacitor you use should be rated for at least 2x the voltage the
motor is running off on. 4x is preferrable. Otherwise the voltage
spikes from the motor will destroy your capacitor very quickly."

so, the voltage is important with 100V being the minimum. It should be ceramic to stand the heat and I will start with 47 mF.

I will send a pic when I get the bloody thing off my camera.

Fixed it!

Here is a pic of the back of the motor with a broken capacitor (yellow component). 0,45M I think means 0.47=uF, M=25% tollerence and 100V = 100V

here

Soldered another cap (green) to test and it all worked.

green cap

One other thing. The fan sucks a lot of current, so weak battery may only spin it and not at the intended speed which I measure to be 4220 rpm. I think that the spec is 4200 rpm.

A job well done...and it didn't cost a bomb to fix!

Hi All.
Away for q few days so slow on to this. The capacitor is there as an interference suppressor to reduce the electrical noise when the fan is running. BMW did a set for use when Police radios were fitted which included capacitors across the fuel injectors as well as other electricl noise sources.
Regards,
K-BIKE

Hi,
Yes, on further reading the cap does reduce the interference generated. It is a standard DC motor installation thing and the cap value is not important.

The two recommendations in literature are:

1. heat (get a cap that can take it, like ceramic), and
   
2. voltage: recommended value is 2 or 4 times the DC voltage. I used 0.47 uF, 100v caps because they are common.
   

This is great information. I hope it is still here and that I can find it when my turn comes! Thanks for sharing!
Dave

Hi Dave,
Don't worry it is well known so we will be able to help if and when the time comes.
Regards,
K-BIKE

For the document collection. Note the fan part number. The new fan looks a better option wrt bearings and construction.

http://www.k1100rs.de/images/8/83/L%C3%BCftermotorreparatur.pdf

it is still on the Bosch books as a valid part number, or at least I think that this is the unit:
http://www.boschmotorsandcontrols.co.uk/elektromotoren/produkt/0130007027/index.htm