Hi!
I'm looking into a small issue I'm having.
Has anyone tried reading the resistance of the aux fan?
I've measured mine, it changes when turning the fan, sometimes as high as 100 ohm, other times as low as 4-5 ohm.
I've searched for this info but was unable to find somebody that had made this same measurement.
If anybody either has it or can check it'll give me a big hand in finding if my issue is with the fan itself or somewhere else in the line
Thanks in advance!
I'll try to take a look tomorrow, I think I have a spare fan.
But... IIRC the resistor for it is ~.6 ohms, or less than one ohm. Not positive what the current draw on it is without the resistor, but 13-15 amps sticks in my mind, which would indicate a resistance of less than on ohm as current is greater than voltage. Spinning it won't work, I can't explain it not being an EE, but I know it doesn't work.
Should have clarified on those measurements, what I meant is that on some positions it measures 4-5 ohm and on other it goes as high as 100. Not that while spinning it I took measurements. Not sure if this is because the brushes have better or worse contact with the collector or something else.
Finally remembered and broke out the meter in the shed yesterday. I didn't power it up, but I'm nearly certain the fan is good, however my readings were all over the place. I think I had a low of 24 ohms and a high of over a hundred. Sometimes it even seemed open, electrically. Very odd.
Thanks Mike!
That's kind of what I had at the beginning.
Over the weekend I removed the fan from the car, disassembled it, greased the bearing and the bushing, lightly sanded the collector and the brushes and cleaned the collector afterwards with contact cleaner.
Now it's almost always near 0, about .25ohms, when moving it my multimeter goes crazy because it's producing voltage, but as soon as I stop moving it it goes to that value.
Tried it outside the car and it now spins with less noise, I don't think it necessarily spins faster, but for sure it's quieter.
Btw, if it's useful for anybody, while googling what to do with the bearing in the front cover, I did find that aux fans for W123/126 and probably some other mercedes benz models are very similar inside, and they do remove the rivets on the front cover which houses the bearing to replace it with good results.
