E30 M3 Fan Resistor

Cheers rob.  That makes sense.  Although I swear the low speed fan is correctly running at low speed, you can feel the high speed one a mile off.  Seized fan sounds right too.  Ive only had the car a few weeks, before that it was in storage for 6 months, and the fan had to be manually freed because it wouldnt cut in, it was in fact slightly seized.  If I keep the set up like this, whats the worse that can happen?  Fan will burn out?  After how many hrs use you reckon?  Everythings sweet right now.

Zain.

Zain,

On the low speed circuit the resistor reduces the power to the fan so
that it runs at a lower speed.

If you have now bypassed the resistor then your fan will probably be running at higher speed for both low and high speed circuits as there is nothing inline to reduce the power.

I think that your fan motor may be knackered and that's what's causing the fuse to blow.

As they get old the bearings start to seize up and so the fan needs more power to turn. This effects the low speed circuit first as the fuse is only 15A so it keeps blowing.

Now that you have changed the fuse to 20A it cant blow, if you replace the resistor again it will once more be overloaded and therefore melt. Fuses are there for a purpose and protect the circuits from damage - at the end of the day it's blown and it's telling you something isn't working as it should.

I would look into buying a new fan, make sure you have replace the 15A fuse on the low speed and check a 30A fuse on is fitted on the high speed and you should be ok.

I always go for OE parts, on something like this - you know it will work, solve your problem and last another ~10 years


Hope this helps, good luck

Rob

Zain, Yes kept getting red hot then breaking. I had it checked out by an electrician who couldn't sort it. It was mounted in the correct position behind the centre grille (as far as I am aware)

Just out of interest, does anyone on here have an aftermarket fan on their car. Any other ideas other that Kenlowe?

Zain, I had this exact same problem!

After changing that resistor about 4 times, I have decided to put an aftermarket fan on mine as soon as it is back on the road. The high speed fan will still come on at about the 3/4 mark but I wasnt entirely happy with this. I shall probably go down the Kenlowe root with an adjustable thermostat. Good look in sorting.

Jim.

Hi all

Im new to all this, so would appreciate a little help from you fellas.

My brother uses this quite a lot, rezaq.  Anyway, Ive just bought a lovely E30 M3, on a H plate, 1 UK owner.  I love it.  But, the low speed fan didnt cut in, and with the help of this forum we discovered I had to change the resistor which sits on the fan housing.  I changed this, and everything was perfect.  Then, nothing, dead again.  Ive discovered the resisitor, which I had to tie wrap onto the bottom of the fan housing as the screws on the old resistor where seized shut, had heated up so much it melted the plastic tie wrap and the area it was sitting in.  I am guessing its overheated and burnt out, great £30 invested there, so what Ive done is just bypassed it, and hard connected the connections.  Seems to work fine now, cuts in, both high and low speed.  The fuse now needs to be 20amp though, as opposed to the 15amp which then couldnt handle the new resistor bypass.  Any ideas what this resistor did?  Regulated the power?  Any harm with this new set up?  The high speed cut in uses a 30amp fuse, so this 20amp wont exactly burn out the fan will it?

Thanks

Zain.