Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Plus4 Fog switch not working

Mark.... I'm an 'old school' car owner but I'm presuming that even in the modern car world the fog light doesn't go through the ecu or half a dozen computers... There's only a finite number of things that will make it not work... Rigging in a complete parallel circuit seems a bit drastic (unless, say, there's a wire break somewhere in a wrapped loom and it's going to be easier to run a new wire than dig it out).... With a meter or test lamp you should be able to chase power into the switch, out of the switch, other end of the wire to the light and into the bulb holder..... If you think the switch is dodgy the first two should confirm.

K

Logic would say why make the function of a rear fog light switch complicated, just take power from the headlights and make the switch a momentary function with a relay latch, so when you use the car next time the fog light is off until you push the button again. Simple. However Morgan have taken the more complex route and put that function on the printed circuit board, thus creating a nice little earner when the pcb fails.

Prior to posting the above, I checked out The Road Vehicles Lighting Regulations 1989 on www.legislation.gov.uk and as far as REAR Fogs are concerned could not see any reference to tying in with headlight operation.

Teknome... Thanks for that... I should have guessed it was more of a problem than just chasing volts...... I presume there's a thread on the subject on here somewhere.... Will have a look out of curiosity (my car has none of this circuit board voodoo)

K

There is an off the shelf solution from Car Builder Solutions

REAR FOG LIGHT CONTROLLER for new IVA rules

https://www.carbuilder.com/uk/rear-fog-controller-for-new-iva-rules



Quote - In June 2013 the rules for switching on and off your Rear Fog Lights changed. Now, the Rear Fog lamps must only be lit when the Dipped Beam, Main Beam or Front Fog lamps are lit. The Rear Fog Lamps may continue to operate until the other lights are switched off. The rear fog lamps must then remain off, even if the other lights are switched on again, until they are deliberately switched on again. This is to prevent people driving off to work in the morning with the rear fog lights glaring after forgetting to switch them off the foggy evening before. Just follow the instructions and connect the four wires of this simple little module into your lighting circuit and you'll comply. Job done.


Considering the price and availability of the bespoke Morgan pcb it is probably worth designing a work around using one of these for £36

I don't know when Morgan started using a pcb assembly, but my 2004 4/4 had one. From memory it may have been around that time that the new dash layout came in.

Mike

Thanks, That ‘s worth knowing Mike. However, I guess MOT rules would be applied to whatever legislation was current when the car was originally built, so it may or may not apply to the urgent need of this original thread enquiry. Who’d want to be an MOT inspector??