Fuse box upgrade

[gucu]

Hi All

I hope everyone is well and enjoying the change in weather!

I have added a tow bar to my Minor and will shortly be adding a led reversing light, two front spots and a lighter socket. Should I upgrade the wiring loom and also install a larger fuse box please? If yes, how would you go about it please?

Thanks

Rich

[Bill_qaz]

I have spots,reverse light a d 12v accessory socket. If you take a fused supply from the battery with appropriate gauge wire then you are not using the original minor wiring.

[geoberni]

Well there's more than one way to skin a cat, if we're allowed to use such old phrases these days.

You have to remember that the original wiring is only protected by 2 fuses, or 3 if you count the later cars having the extra one for side/panel lighting.
Headlights never with a fuse.
When adding extra equipment, I would recommend new wiring and a suitable fuse box. How you go about it is your business, and whether you want to have 'modern stuff' on show.
You could use a modern blade fuse box, and have it under the bonnet or hidden under the dash.
You could get a 'period fuse box' with glass fuses and add it near the original.

The choice is yours.

My SII was rewired to indicators, but the trafficators were still there, unused. I reinstated the trafficators with relays to let me disable them if travelling at higher speeds to prevent damaging them. All powered from a small blade fuse box and together with the relays, hidden up under the dash.

A past owner fitted the car with a junction box on the green wiring, separating them all out from the screws on the fuse box... I've no idea why, but it could have easily been a separate fuse box (Photo from 2017 when I brought him).
.

20170902_204943.jpg (526.66 KiB) Viewed 73101 times

[bobtail4x4]

I went for the second lucas fusebox option,
next to the original it dosent look out of place,

[svenedin]

I am certainly no electrical expert but I would approach this from first principles.

Certainly with the later cars (I am not familiar with all the variations) absolutely everything except the starter motor is powered by 1x brown wire from the solenoid (which is in this case just acting as a connection terminal). I do not know what the rating in amps of that brown wire is but this must be considered before major additions. There are empty connections at the fuse box that could be used to run a new green wire (ignition switched live) or a purple wire (permanent live) but consideration of the load on the ignition switch needs to be considered for switched live. In other words it needs to be thought through and the load in each part of the circuit considered. Back to the OP and an LED reverse light, this is a very low current device but the lighter socket is not. One needs to consult the relevant wiring diagrams and the current rating of the various wires in the circuit. To be done well and safely it needs some thought!

Stephen

[Bill_qaz]

I took a positive from battery side of starter switch via a blade fuse holder. The negative from my isolator and run new twin cable into car to power accessories so seprate from original wiring.
Also when isolator is turned off from inside the car the circuit is dead.

20240323_125856.jpg (1.3 MiB) Viewed 72774 times

[gucu]

So leave the original in place but adding a second fuse box is a good idea and definitely get experts involved!

Thanks I will talk to my garage.

[Meggie moggy]

After a fire from when I first purchased Meggie I pulled all the extra wiring out that had been very poorly installed. Then looking at the cable CSA of original wiring compared to the 35A fuse I thought it may be beneficial to install a secondary fuse box to protect the ignition controlled circuits. I installed a 4 module blade fuse box into a old voltage regulator this has allowed me to lower the ratings on these circuits which (should) prevent excessive heat should a fault occur, it also helps to look reasonably original.

[kevin s]

I went mad and fitted 2 12 way modern fuse boxes under the dash, one for the permantly live the other for the ign controlled circuits, after splitting the loom most of the original wires could be pulled back through the bulkhead and wired into thr fuse box. The feed for them is all new going from the battery via a 2 50 amp maxi fuses then to the fuse box and a ignition controlled relay.

rps20170129_150608 - Copy.jpg (68.21 KiB) Viewed 71616 times

rps20170610_195757.jpg (65.42 KiB) Viewed 71616 times

rps20170603_212648.jpg (86.72 KiB) Viewed 71616 times

Capture wiring.jpg (69.95 KiB) Viewed 71590 times

at first only a few fuses on each box were used but now with heated screens, heated seats. Mapped distributorless ignition, relays for headlights, radio, power outlets etc most are being used.

[MinorOCD]

The upgrade to the blade fuse is a good move, even if it’s not original. The cartridge fuse (glass tube with end caps) was never a good solution for automotive applications as they don’t like vibration. Additionally, it’s difficult to find good quality ones these days. The blade fuse (unlike the cartridge fuse) has no soldered joints, it’s made from a single piece of material and the fusing element is formed to the correct cross sectional area for its given rating. It was designed for its inherent reliability and they are widely available.
Also good to fuse the separate circuits.