3 speed cooling fan fastest speed not working
 

Hello to all.
Boring & never-ending question I'm sorry.
I tried a search in the too many threads about it but I've nowhere found a precise answer.
Hence unfortunately another thread... :shrug:

In my 1999 KV6 I guess I've got the 3 speed fan.
Despite that I've read the lower speed was often failing, in my 75 it's the higher one which fails.
With the high temperatures we're suffering at the moment (37°) it would be nice to cure the problem ASAP. :eek:

What should I do?
swapping the brushes? The whole motor?
What could be the simplest and less expensive solution?
Any links much appreciated.

Thanks a lot. :bowdown:

Sorry to answer a question with another, but how do you know that your highest speed has failed?

I'm helping an owner (1999 too) change his completely failed fan on Wednesday, and although I've got some rebuilt fans advised him to get one of these:
https://www.ebay.co.uk/itm/172536315...d0AAOSwfVpYpx0
Justifying the purchase by comparing the low price vs the work involved changing the fan. Even though this will be my 9th or 10th fitting, I still estimate about 5 hrs work.

Keep well

Hello Mike! ;)

How do I know? Well among other jobs a pro made yesterday I had a complete check & diagnostic of my car.
And - I've got the sheet he gave me in front of me - his software (Launch X.431 v. V5.01.016 - don't understand a jot about what I'm writing!) and the report gives one only error:
"p0481 cooling fan relay high speed"

BUT I've just had a check with my TOAF and all the 3 speeds were checked and are working fine! The evidence is I can hear them and particularly the third one as expected! :D

Sorry then mate: I've stupidly repeated what I was told without verifying, even when it's asserted by a skillful mechanic. I guess the guy was fooled by the software he is relying upon...
Why then this error code? Mystery... :shrug:

Arnaud

OK, but sorry I'm confused - a quick check suggests P0481 is the medium speed, yet all are working. Toaf checks all fans speeds even if you've got a 2 speed fan.

Let's go back to the beginning (a very good place to start), look through the grille at the front of the car and see if you there's a silver or gold resistor mounted at roughly the 2 or 3 o'clock position.

Keep well

That's where lies the confusion: I've seen the same mistake about the 2nd or 3rd speed. Actually it looks indeed that the error P0481 is regarding the 2nd and not the 3rd. So why that mistake in some reports? :confused:

I'm sure my 3rd speed is working: it's clearly audible!
I'm not so sure about the 2nd which is far less noisy but the TOAF tells it's Ok. So I rely upon the TOAF. :shrug:

Regarding the resistor in my 1999 KV6, it's obviously silver, as I've just verified today. I guess it could be as old as the car. Not many gold resistors here in France I bet: my seller in 2017 wasn't a connoisseur and kept the car only 13 months (I'm the 4th owner). In the bunch of bills I was given and going back to the end of 2013 (and paid by the previous owner) no such investment.

If the fan has a resistor, what ever the colour, it can't be the original three speed. its been replaced with a later two speed at some point.

Brilliant piece of information!
Thanks a lot. :clap:

So why that weird error on the 3rd speed in their rapport?
And why TOAF is telling me it's testing the 3 speeds?
Are all mistaken?

Could be the way TOAF is set up otherwise it would need a separate test program for 2 speed and 3 speed. Tests first speed, then second but throws up an error because it can't find a third speed.

Think the simple answer is that Toaf (based on BMW INPA) was written with the earlier cars in mind that had the 3 sp fan, the 2 sp ones came later. So Toaf does the checks and activates all speeds even though you only have 2. If you've got good ears the you'll probably notice that the Toaf 2nd speed has exactly the same noise as either your low or high.

Seems your friend's Launch does the same but gives the incorrect result.

Anyway your car is healthy, keep checking the fan as the silver resistors do burn out. Having said that I've got a silver resistor too, but a spare gold one in the garage.

Keep well

TBH I can't say I can hear any difference between the 1st & 2nd gear: had my 3 gear resistor been swapped for a silver 2 gear one at some point, that would explain the fact.
In the end my fan is working properly and that's the point! :D