Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Fog Light Wiring

My 2011 4/4 has a redundant push switch, on the dash, which is designed for the not fitted Air Con. Caution if you are thinking of using this button for fog lights. Try pushing it on with the engine running, then turn on the fan. Magic the button lights up, which methinks means that the pcb is wired/programmed in some way that would interfere with your planned use. Mind you every morgan is different 😎

At the end of the 2016-2014 Classics parts book Rog there are various wiring schematics including three variants of the chassis loom with the first two attributable to earlier models it seems since the last one is dated 2007.

In any case on all three a front fog light switch connector is shown fed from the o/s sidelight fuse12. With the switch present this feeds through to the front wings each side. The o/s fuse together with the n/s one are fed directly by the stalk light switch when sidelights selected. This stalk switch is fed by a further fuse 18 to protect it, in turn fed by fuse 8 in the high current set which fuses the main fuse box. All of latter are fed directly from the battery. Phew!

Draw your own conclusions but I cannot see any intervention by PCB. The rear fog light circuit is a different matter of course to comply with regs.

Hi Richard,

I really should take the time to read your instructions better, 'My Bad' as the youf would say

After reading and digesting your latest comments they promoted me to look back at your earlier instructions.... and low and behold I found this.....



I never expected the wires to be permanently live as this would be deadly, but I was so convinced they were controlled by the fog light switch on the stalk I totally overlooked your critical pearl of wisdom above

I can now see why Morgan went with blue with a yellow trace, I suspect it's because the wires were intended as dual purpose, i.e they could be used with the auxiliary switch to control either a set of driving lights, or a set of fog lights depending on what was fitted. It could also explain why Rog talks of PCB failures, if someone say took the a +12v off the rear fog light to power two front fog lights thinking this was a way to use the stalk fog switch to power all three lights but failed to appreciate the PCB was never designed to carry that level of load, I can totally see why it could fry the board.

So, to control my new front fog lights I now need to source and fit the optional auxiliary light switch, and then use the existing plug and play connector block behind the dash I actually had no idea existed, right up until you drummed it into my thick skull! If that's the case I'd be super grateful can you link me to where I can buy the switch that comes with the right connection, and give me a few pointers on exactly where under dash I should go searching for the mystery connector block, if at all possible a photo of said connector block would be a massive help too

I think you've saved me a lot of head scratching, after finding the blue wires with a yellow trace my next step would have been to put my multimeter on them with the headlights and the stalk mounted fog light switch on too, I would have then assumed the circuit to be faulty and may have even progressed to running the live feed for my new front fogs off the rear fog light relay which by the sound of it may not have ended well for me or Monty

Many thanks for all your help Richard, if you do have a photo of the connector block and can link me to the right switch I'd be very grateful indeed

While Richard's existing wiring option seems by far the best way to proceed, if it does turs out my loom wasn't built with the blue/yellow wires here's another logical approach from Jon (CooperMan), although as I'm powering fog lights I'd be triggering the additional relay from the dip beam circuit not the high beam circuit as Jon has correctly used for his driving lights.

Like Jon I have no aircon, so that 30a fuse protected feed would make a logical choice to repurpose for the high amp +12v supply for my fogs, I have the aircon switch in my dash so I assume if I'm repurposing the aircon fused circuit I could also turn on my fogs with this switch? However, to ensure I blow the fuse before I overheat my additional fog light wiring I would have thought replacing the 30a fuse with a 20a fuse would be more appropriate.



I found the above here....

http://www.talkmorgan.com/ubbthreads.php/topics/555419/2018_Roadster_fog_lights

Either way I’ve now completely moved on from my original assumption that I’d be using the stalk switch, my new fog lights will definitely need a separate auxiliary switch to control them. Hopefully I do have the blue/yellow wires as it seems Morgan built this circuit into the loom to make exactly what I’m trying to achieve a straightforward and safe exercise for their dealers looking to retro fit additional lighting to a customer’s car.

You seem to have the gist of it now Dave. MMC provisioned for the optional front fog or driving lamps to be plug and play. Don't have any pics of dash wiring or even where the optional switch is supposed to fit (is it one of the group of four between dials?) but hopefully Rog with his similar age +4 can help here.

The wiring schematics I refer to elicit quite a lot of info if you know where to look. To this end I can tell you the switch connector you are looking for routes out of the chassis loom at the same point as its multiway dash connector but with 400mm long wires (red/orange and blue/yellow), so probably cable tied out of the way whilst unused. You may be able to see it from under the dash, but again Rog may be able to help.

If you have difficulty sourcing the correct switch to match connector, any single pole on/off switch will suffice and you could connect direct to the two wires after chopping off connector. Pardon me for stating the obvious but disconnect battery before dropping dash.

An interesting thread Richard. Sorry I can’t help with either request. I’ve never considered fitting fogs before but mind you those Marchals do look very attractive…

Can’t help thinking if I was going down this road I might leave the ‘plug and play’ alone and use new wiring, relay, fuse and switch.

Think it’s already been said, but that (almost) redundant aircon switch, must have some existing connection with the heater fan as if depressed, it will show the yellow snowflake symbol lit up, whenever the blower is on. Just saying…as you might find everytime you put the fogs on it might start the blower or when you put the blower on, it might start the fogs!

The above definitely remains an option, but only if the blue/yellow wires and the now infamous yet unphotographed behind the dash switch connector block both remain elusive

Surely using the existing rear fog light circuit to energise the tiny coil in a standard 30a 12v relay isn't going to do any damage to the PCB, after all it's only going to be pulling 150 - 200 mA

Like this all three fog lights would be triggered by the same fog light switch on the stalk and the PCB would only see 200mA tops, it would also retain the logic circuit where the fogs can only be deployed with the headlights switched on, and the 20a fuse protected live feed to power the fog lights would come direct from the battery ensuring an unimpeded current supply from source.

The only disadvantage being I'd need to build and run a simple separate loom for the fog lights and relay, assuming it exists I’d still far prefer to use the existing auxiliary light wiring Morgan intended to power driving or fog lights, but if it proves problematic to locate at least there’s plenty of other safe options to light up my lovely Marchals

It might be in the background here? Lurking next to the fag lighter socket that was located in the side wall of the glove box (it’s an old pic of a mod to re calibrate the fuel gauge that I did to my 2006 car).

Nice one Rog

To make 100% sure I've correctly understood what you're referencing here, I've rotated the photo and marked the connector I believe you've identified with a red arrow.



The green arrow points to what may well be the blue wire with the yellow trace, I've zoomed in below and it does look like the tracer in the blue wire could be yellow in colour



Actually if we zoom in even closer and turn up the colour stauration it seems even more likely the tracer is indeed yellow



Please let me know if I'm looking at the right connector, also if someone could link me to a post that covers dash removal I'd be very grateful.