Morris Minor Owners Club

The attached letter was sent to the https://www.midgetandspriteclub.com/ and could be relevant to Minor owners. Having looked at the wiring diagram, covering my late Traveller (Which is negative earth), it appears there is a fuse, between the light switch and the rear lights but the front lights are unfused. The supply, to the switch, looks to come from the voltage regulator. Has anyone fitted a fuse to the front lights and if so, where did it go and what size was it?

Most of the variants in the "N" section of my workshop manual show no fuse. But BL Drivers Manual AKD3922 shows a 10A fuse protecting front AND back side/tail lights (inc number plate). Though they should take only 2.5A in total .
Incidentally, does anyone else find these WS Manual electrical drawings a nightmare to trace? They run many of the paths next to each other; perhaps reflecting that they are all in same cable bundle. But it disregards the logic of the separate functions, and makes me go boss-eyed.
It needs the logical transform that (my near neighbour!) Harry Beck gave to the London Tube map in the 1930's. And the name of the device and the wiring colour need to be marked on the drawing, not tediously cross-referenced via a numbered key.
PS I've got a (colour) print of just such a re-visualisation somewhere . But it doesn't cover every variant.

Correct. There is no fuse for the lighting. They seemingly didn't want to leave people with no lights.
The fact that nearly the entire electrical system is on a single 35a fuse is quite ridiculous. I'm ignoringthe 35a fuse that serves only the horn and internal lights
They belatedly fitted the 10a for external lighting excluding headlamps plus speedo panel lights.
My car has a new loom fitted about 25 years ago but any car on the original loom is really on borrowed time when it comes to electrical fire risk.
A well maintained wiring system will give no problems, but a 60-70 yr old loom is asking for trouble. As the letter stated a red wire had been allowed to short out....

mike1864 wrote: ↑Sun Dec 21, 2025 4:55 pm
Incidentally, does anyone else find these WS Manual electrical drawings a nightmare to trace? They run many of the paths next to each other; perhaps reflecting that they are all in same cable bundle. But it disregards the logic of the separate functions, and makes me go boss-eyed.
It needs the logical transform that (my near neighbour!) Harry Beck gave to the London Tube map.......

There is a member who drew a set of colour diagrams and I think he sells them on ebay. He's not active here much these days having gone over to the farcebook side.
Personally I downloaded a pdf of the AKD530 to be able to zoom in on it

Any help?

Bill_qaz wrote: ↑Mon Dec 22, 2025 12:13 am Any help?

I've not seen that colour DB10 system before

The ones I knew of were the Brian Hawley ones, I just couldn't remember his name last night

Well done to Brian. Worth printing out, laminating, and keeping in the car

Thanks all. There are some things (Not necessarily electrical) were I find the Haynes manual easier to follow. As to wiring, I at least find the Minor (Lucas) diagrams easier to follow than Bosch.

Blaketon wrote: ↑Tue Dec 23, 2025 9:29 am As to wiring, I at least find the Minor (Lucas) diagrams easier to follow than Bosch.

I had problems earlier in the year with the Diesel Particulate Filter (DPF) Pressure Switch preventing my Kuga doing a DPF clean cycle.
It only has 3 connections to it but it took me ages of scrolling through the official Ford online diagrams, jumping between drawings, to find out which of the 3 were Supply, Earth and the Output to the next component in the system.
I did eventually trace it and was able to confirm the replacement Switch I had fitted was only giving a steady voltage output, no matter what revs the engine was doing . Having changed the switch once, I'd been chasing around the system, even taking the DPF off twice for a manual clean.
Another new switch sorted it.

A power probe is a very useful tool for diagnostics quickly checks ground and supply and can provide either for component checking. I also have a cheap scan tool, it puts a pulse down a wire, then you run the scanner externally along the loom and the tone change tells you where the break in the wire is. Multimeter checks continuity but cannot tell you the point where it lost
Less useful on short wiring runs but I used to troubleshoot on trucks, were the loom can be meters long between connections , so good to know where to open the loom