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MG MGF Technical - MGF - Fan only working on speed 3 or above

Hi all!

I've got an strange problem (with the MG, that is...).

The fan has stopped working on speed setting 1 and 2 - but still works fine on setting 3 and 4.

Has anyone ever heard of anything like this before?

Cheers,
James.
J Phillips 1

It's almost always the resistor pack - see http://homepage.ntlworld.com/tim.jenner/p996kvx.htm under Technical.

Tim.
Tim Jenner

I agree with Tim sounds like resistor pack easy fix as long as you can get the part.

Tom
Tom Randell

Someone, (can't remember who) suggested an electronic alternative as a one-off and even produced a cicuit diagram, but not sure if this was ever built.

Chris
Chris


Hi

Anyone know where we can get resistance wire ?

David
D Brunton

Try Maplins
Rob Bell

Hi all,

Have a PWM-unit since nearly 3 years now. Continous control of the fan-speed and no worries for broken /burnt resistor-pack.
Just wonder why no aftermarket people offers this easy gadget. If the work involved in replacing the standard 4 setting switch for a potentiometer seems too much it should be easy to use the standard 4 "pre-set" speeds for the PWM unit as well... / Carl.
Carl

I've just had to go and look up what a PVM is: http://www.netrino.com/Publications/Glossary/PWM.html

Couldn't you have simply used a potentiometer Carl - or is there an advantage to using a PVM?
Rob Bell

I'd guess a pot would be out because of the amount of power it would have to dissipate at low fan speeds.

Tim.
Tim Jenner

James,

If you get the problem sorted do you think you could post how you fixed it on here please - mine suffers from the same problem.

thanks

nick
Nick D

The PWM-tech. is allready on board the "F"! Thatīs the way the inner light gracefully shuts down. But probably there were a lot of old stuff lying around (and at a low price!) for the ventilator unit.
A very simple PWM unit, as the one I put together works fine ,has only one drawback. At one certain low rev. there is a slight audible resonance in the electric motor. But this is only in a very restricted rev. band . So easy to avoid that specific setting.
IMO it would be a perfect thing for the aftermarket guys. The potentiometer for the PWM unit carry only a few mA - so no problem. The only problem with a pot. is to make a snug fit into the dash. Using the original switch with its settings is so much simpler.
/ Carl.
Carl

the resistor pack gone my went on the 1 setting the others are fine

darren jeffery

Easy enough to swap the basic resistor pack if you don't mind lying on your back with your head under the dash. Great fun getting out several times to get the tools you forgot!
M Cunningham 1

Carl

Sounds like your switching frequency is too low, magnetostriction I believe. The frequency probably needs to be about 20KHz.
Ken Waring

Yes, you are spot on ! But found out when all was mounted and the speed-knob lined up etc.etc. So maybee some winters day I do a change on the two 555īs as the car is on stands during "off season" .
The IRF 540 FET can take the freq. raise easily.
If I had to use my car for winter driving together with (the never used!) hardtop it would be a nice thing to steer the fan-speed and hence get a fairly steady temperature.A simple NTC sensor at medium height in the cabin would do the trick.... / Carl.
Carl

Are details of the circuit on Dieter's website yet Carl? :o)

Sounds interesting - I imagine that a few of us may want to try this out for ourselves :o)
Rob Bell

This thread was discussed between 27/10/2005 and 31/10/2005

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