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MG MGF Technical - MK2 Front Fog lamp switch

I have just purchased a new Front fog lamp switch to fit my converted MK1 to a Mk2. The keying was different which i removed however, the switch and consequently fog lamps are always on and the illumination on the switch is not working.

Does any one know if the switch is wired differently from MK1 to Mk2 or have I just got a faulty switch unit.

Also posted in General section
Chris Catchpole

If this helps anyone with the old switch i am getting full resistance across pins 1 and 4 with switch on and nothing when off

With the new switch I am getting full resistance across pins 1 and 4 also small resistance on 1 & 5 and 1 & 3 in the On position

And full resistance across pins 3 & 5 when off, does this mean there is a short in the switch
Chris Catchpole

Chris, have you got the fog and rear demist plugs connected to the wrong switches? Sorry - I know this sounds basic, but from what I'm told, the fog loom plug will only plug into the demist switch unless the keying is removed. Apologies if you've already covered that potential pitfall!!!:o)
Rob Bell

Rob, I have removed the keying on all connectors. I have the rear Fogs working ok. I have connected the rear demist switch but have not tested it because I have the soft top on.

The new MK2 front fog switch is on all the time, I connected a meter to the switch and found resistance over pins 1 & 4 when in the on position and pins 3 & 5 when in the off position, the switch illumination is also not working, so it is either a short in the switch or the switch is wired differently between Mk1 and Mk2. I have ordered another switch and will try it at the weekend and post my findings.

Chris Catchpole

I need to check the wiring diagrames Chris - Mk1 v MY2000 - this should help shed some light on this predicament. Odd that no-one else has reported this problem on their MGF - but might be a question that no-one has yet tried this conversion with front fogs fitted?

>> the fog loom plug will only plug into the demist switch unless the keying is removed <<

Hmm, that should read REAR fog loom plug...
Rob Bell

Nuts. The copy of the MY2000 wiring diagrams that I have do not include the front fog circuit! :o(

I can't help you very much, but I wonder if your original diagnosis is correct - namely that they altered the wiring inside the switch with the MY2000 - certainly they did exactly that for the window lift switches! :o(
Rob Bell

Mike does TF conversions doesn't he? Mike speak up we can't hear you.
Chris Catchpole

Hi Chris,

I did this last year - unfortunately the best result I could get was for the illumination light to come on and the fogs functioning (with no switch light). This may be a starter for you, but if you manage to wire it up correctly I'd be most interested in your results.


Colin can you remember which wire went to which pin in the socket
Chris Catchpole


MK1 versus MK2 front fog switches are different. Both wiring diagrams have never been included to any diagram issue.

Get an MK1 and compare directly.
Just my few pence.

Good luck
PS. let me know the results, I'll be pleased to hosting on the fog light site :)
Dieter K.

Hi Chris,

I'm afraid I'm in Madrid at the mo, so have no access to either my car or the diagram that I think I still have.

I'll be happy to send you the details once I get back to the UK - should be in a week or so.

Lucky you, I would appreciate a copy of the diagram when you return my email address is


Chris Catchpole

The plot thickens , I have just heard from Mike and he said they do not have any problems with Front Fog switches when doing the conversions.

This is all now a mystery to me and it looks like disection of the switches may be necessary.

Chris Catchpole

This thread was discussed between 27/01/2004 and 04/02/2004

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