Fitting some safety fuses to an early car

[John A. Ross]

There has been quite a lot written about every imp apart from the very last ones having no fuses. Sounds dangerous but I would have to say that the amount of incidents I know of are few and far between, those I do know of were almost total losses though and the wiring is not getting any younger, most of it exoposed to extended temperatures over most of its life living beside the heater hoses.

Still, an early binnacle car is not so bad to drop a few fuses in ad-hoc, especially if you have already did the work to add an alternator (not so bad with a dynamo either but certainly easier with a alternator).

So where to begin, how about the beginning

The battery

This is what we had with the dynamo



This is what we want, much simpler

[John A. Ross]

Some more images of the key places, watch out for them in the videos

Part 1 covers us up to the interior light
Part 2 covers us for most of the rest
Part 3 I will do the actual work and test itm, set fuse values etc.


Wiper motor, easiest of the lot and has to be done at the motor, the white wire shown is live with IGN=ON and the motor switch switches to ground

Pull the white wire, insert fuse, done

This fuse needs rated to include situations like dry windscreen




This is the sidelight, dip and main beam bundles, the bullet connectors can be used to insert the fuses if you desire individual protection

The full light circuit protection is through the back of the lighting switch/dip/main/flash switches and has to be accessed with binnacle removed




Ignition system and brake lights, insert fuse at coil, the brake lights feed from that point



This shows a small error as regards the horn, the wiring diagram shows the horn as being switched live, when it is actually switched to chassis.

The fuse needs inserted in the brown wire



Some work will be done here to reroute the battery connection and connections to the solenoid to add fuses



The alternator wire will be upgraded so it can handle the max output of the alternator, at same time we will add a fuse inline to limit it for the rest of the car.



Where we want to go



Work in progress

[John A. Ross]

And the next lot

We will be adding a fuse to these connections, we need to break in to one wire with the binnacle removed








Flasher unit and indicators is an easy one





Horn wires do not relate to the wiring diagram, but wires identified and noted.




Protection for the interior light, with or without courtesy light switches, it is a nasty setup as the wires just rattle around inside the windcreen pillar.




Lighting wiring, you can protect individual circuits here for side, dip, main etc. but we will just be adding a main fuse.

[John A. Ross]

And the part 1 and part 2 videos

Part 3 will be about a week away

[John A. Ross]

Well tonight did not go as planned

Started to remove the extra loop for the ignnition feed, found issues on the alternator wiring which including no point adding a 30-40A fuse to wire that was only good for n25A or so when new !

Things never go to plan and sometimes you get a bump in the road.

The car had had an alternator mod done, pretty well but I could not live with the under rated wiring especially when adding fuses, so had to strip the loom,

Also managed to mop up the extra coolant temp sender that had been added and remove the previous lamp of doom wiring which used to be the oil pressure switch and coolant temp switch.

Once the existing mods had been tidied up and the excess wiring removed e are back to a place we can add the fuses in, guess what, I forgot the damn connectors I needed and it was late, so will need to be a part 4 or maybe 5 now !

• Part 1 covers from engine bay to interior light
• Part 2 covers the rest
• Part 3 will be the actual fitting of the fuses and testing (still to come)
• Part 4 was fixing some alternator wiring and the temp gauge modifications already in the car
• Part 5 adding some of the fuses in the engine bay and bonnet area
• Part 6 adding fuses to the binnacle and dash area

See below latest installment

[John A. Ross]

And it goes on and on

After remebering the parts this time we finally got the engine bay sorted and the ignition fuses in.

A small stop to show the crimped ends I have been using which are same style as factory.

Then off to use those to fuses the ignition coil and stop lights, then the wiper motor, would have helped in testing if I had actually fitted a fuse, homer moment, doh !

I think the cold was getting to me

[John A. Ross]

Change of direction for parts 5 and 6

It has been a while before I managed to get the final parts done and in-between I had a change of direction as I wanted to keep things as simple as possible and not need to remove the binnacle. I have been quite busy and fighting a terrible cold (not covid thank goodness) and decided to simply add the fuses at the ignition switch as that is the easiest place for basic protection and without getting really stuck in to the car, basic is best we can do. Rating wise we need a cascade of values and will cover that in part 6

The final part at last. Rating the fuses, now we have the ignition switch splitting the supply from the engine bay into three. The more observant will have noticed the thickness of the main feed, its small, so you really need to watch the loading when adding anything extra like spotlights and so on.LED conversions, fantastic idea to get the current down. Some of the items such as wipers and lights are as expected, other such as horn and heater blower can be a eye opener, 4A at least. Nearly as much as the dip beam units each ! Now we fused at a higher rate in the engine bay as we need to count all items that will pull current, bear in mind the dynamo in the original design was only capable of 22-24A at higher revs. As you can see with lights, wiper, hit the horn or heater blower and indicators, it can eat that up easy.