Hello,
I am/have fitted a number of extra electrical items to my 1098 Minor - i.e. CD player, reversing lamp, boot light etc.
I forsee having lots of wires coming off the possitive terminal on the battery which is going to clutter up my engine bay. Is it possible to fit something like a second fuse box so that all these secondary items are wired into one place and just one lead needs to go to the battery?
Many thanks for your time,
George
Extra electrics...
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GeorgeHurst
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Peetee
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Yes, like this:
The brown wire is common to all the fuses and goes to the battery terminal so all are live with ignition off but you could arrange it so all/some are ignition live only.
I chose a box with fuses of the same style and as original rather than the common replacement box that holds blade fuses.
The brown wire is common to all the fuses and goes to the battery terminal so all are live with ignition off but you could arrange it so all/some are ignition live only.
I chose a box with fuses of the same style and as original rather than the common replacement box that holds blade fuses.
Older and more confused than I could ever imagine possible.
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GeorgeHurst
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Rob_Jennings
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The first steps in adding new accessories to the Minor will normally involve adding a new fuse box to feed the new devices. This is to be recommended as the current fuse box, wiring and ignition switch are already well loaded, and at 40 odd years old, there is no harm in putting in a few new wires for the new items. There are some accessories that must have a separate circuit due to their high current load, e.g heated screen, Fog lights etc. Never be tempted to increase the fuse ratings in the fuse box, they have been selected to protect the connected devices and wires, increasing them may result in severe damage or a fire in the electrical system.
To protect the ignition switch from being overloaded I would strongly recommend the use of a relay to create a new accessory switched feed.
The following instructions apply for both negative and positive earth cars, where 'live' is the main battery feed, but be aware that modern accessories may be polarity conscious (radios etc) and it may be wise to convert to negative earth if you have not done so. Also consider an alternator upgrade if the new accessories are high current consumption devices.
Always remove bath battery connection when working on the vehicle electrical system. Remove the 'earth' or body connected terminal first followed by the 'live' second. Reconnect in the reverse order.
Fuse Box:
A good 'period' fuse box to add to the minor is a Lucas box that contains 2 (as per the original) or 4 fuses (from a Mini, or Triumph). These will neatly fit on the bulkhead near the current fuse box and regulator or could replace the position of the regulator on cars with an alternator fitted (regulator not required). Generally it is best to keep it to the near side of the bulkhead since most the the wires for switches are likely to pass through the same holes in the bulkhead as the original wiring loom and this saves routing them around under the bonnet.
EBay is a good source for locating a period fuse box, although many of the parts suppliers also sell them. Its a good idea to get one with Lucas push on terminals that appear at the sides, this will match the connectors on later cars and allow it to be surfaced mounted on the bulkhead without problems. Try and find one that comes with a cover, just to help keep the damp weather and oil off the fuse connections.
Mount the fuse box with sufficient space to get wires around it. Drill two smallish holes in the bulk head, treat with rust inhibitor and simply screw the new box directly on with a couple of self tap screws suitable for outdoor use.
Permanent Live Feeds
For accessories that require permanent power (fed even when the key is removed) it is simply a case of running a wire from the live battery terminal (or possibly the solenoid) to the fuse box, and then taking the accessory feed from the fused side. Make sure you use automotive cable of sufficient rating. I would suggest it should be at around 40 Amps or more from the battery to the fuse box, this would allow a single wire to feed 2 or 3 fused outlets. The rating of wire for each accessory will depend on the current they draw. always select higher rated wire than you need, and in all cases higher than the fuse fitted in the box.
Always minimise the number of accessories on one fuse, adding new fuses as required. The maximum fuse rating should not exceed 35 Amps
To keep the wiring simple and neat I would suggest a single wire to the first fuse connector (of sufficient rating) and then short wires connected between subsequent fuses (using the heavy duty cable for all these connections). Most of the period boxes have 2 connectors at each side of the fuse making this simple to do. But also be aware that some fuse boxes already link 1 on more fuses with metal links under the box (visually inspect the box for this before fitting).
Switched Live Feeds
The ignition switch already carries a fair load in the electrical system and it is recommended to use a relay to operate switched feeds. An automotive relay only costs a few pounds, and is a lot cheaper and easier to replace than burnt out ignition switch.
Select a relay designed for automotive use, the coil must be rated for 12v and the contacts should be rated 30 Amps or higher. Many of them are designed with Lucas push on spade connectors and these will be the easiest to wire or replace in the future.
A relay works by using a coil magnet that pulls a bar across a set of switch contacts. When no current flows the switch will be in one state (could be open, closed, or connected to one contact set) a small current applied to the coil will change this state. So only a small load is presented to the ignition switch, and yet the output can switch many amps safely.
It is important to identify the correct terminal on the device before fitting, and most are marked with a simple diagram indicating the coil and contacts. The contacts are always labelled in the 'off' position, so that it should be clear which contacts make and which break when the relay is on. Some relays may have a coil that is polarity sensitive (a protection diode is included in the device to stop interference) and it may be necessary to wire the coil correctly according to the car polarity, most automotive relays do not have this feature.
Mount the relay near the new fuse box (it could be mounted under the same screws as the fuse box if space permits). Wire one side of the coil to the car body or 'earth', the other side of the coil should then be fed from the old fuse box where the white wires connect. These is the feed from the ignition switch and will mean the relay is energised when the key is on. Run a wire from the new fuse box Live feed to the normally 'off' contact on the relay and then from the 'center' contact to the new fuse box. (using the contacts like this mean there will be no live terminal on the relay when it is off and so is much safer) The switched accessory can then be be fed from the fused side of the fuse box
To protect the ignition switch from being overloaded I would strongly recommend the use of a relay to create a new accessory switched feed.
The following instructions apply for both negative and positive earth cars, where 'live' is the main battery feed, but be aware that modern accessories may be polarity conscious (radios etc) and it may be wise to convert to negative earth if you have not done so. Also consider an alternator upgrade if the new accessories are high current consumption devices.
Always remove bath battery connection when working on the vehicle electrical system. Remove the 'earth' or body connected terminal first followed by the 'live' second. Reconnect in the reverse order.
Fuse Box:
A good 'period' fuse box to add to the minor is a Lucas box that contains 2 (as per the original) or 4 fuses (from a Mini, or Triumph). These will neatly fit on the bulkhead near the current fuse box and regulator or could replace the position of the regulator on cars with an alternator fitted (regulator not required). Generally it is best to keep it to the near side of the bulkhead since most the the wires for switches are likely to pass through the same holes in the bulkhead as the original wiring loom and this saves routing them around under the bonnet.
EBay is a good source for locating a period fuse box, although many of the parts suppliers also sell them. Its a good idea to get one with Lucas push on terminals that appear at the sides, this will match the connectors on later cars and allow it to be surfaced mounted on the bulkhead without problems. Try and find one that comes with a cover, just to help keep the damp weather and oil off the fuse connections.
Mount the fuse box with sufficient space to get wires around it. Drill two smallish holes in the bulk head, treat with rust inhibitor and simply screw the new box directly on with a couple of self tap screws suitable for outdoor use.
Permanent Live Feeds
For accessories that require permanent power (fed even when the key is removed) it is simply a case of running a wire from the live battery terminal (or possibly the solenoid) to the fuse box, and then taking the accessory feed from the fused side. Make sure you use automotive cable of sufficient rating. I would suggest it should be at around 40 Amps or more from the battery to the fuse box, this would allow a single wire to feed 2 or 3 fused outlets. The rating of wire for each accessory will depend on the current they draw. always select higher rated wire than you need, and in all cases higher than the fuse fitted in the box.
Always minimise the number of accessories on one fuse, adding new fuses as required. The maximum fuse rating should not exceed 35 Amps
To keep the wiring simple and neat I would suggest a single wire to the first fuse connector (of sufficient rating) and then short wires connected between subsequent fuses (using the heavy duty cable for all these connections). Most of the period boxes have 2 connectors at each side of the fuse making this simple to do. But also be aware that some fuse boxes already link 1 on more fuses with metal links under the box (visually inspect the box for this before fitting).
Switched Live Feeds
The ignition switch already carries a fair load in the electrical system and it is recommended to use a relay to operate switched feeds. An automotive relay only costs a few pounds, and is a lot cheaper and easier to replace than burnt out ignition switch.
Select a relay designed for automotive use, the coil must be rated for 12v and the contacts should be rated 30 Amps or higher. Many of them are designed with Lucas push on spade connectors and these will be the easiest to wire or replace in the future.
A relay works by using a coil magnet that pulls a bar across a set of switch contacts. When no current flows the switch will be in one state (could be open, closed, or connected to one contact set) a small current applied to the coil will change this state. So only a small load is presented to the ignition switch, and yet the output can switch many amps safely.
It is important to identify the correct terminal on the device before fitting, and most are marked with a simple diagram indicating the coil and contacts. The contacts are always labelled in the 'off' position, so that it should be clear which contacts make and which break when the relay is on. Some relays may have a coil that is polarity sensitive (a protection diode is included in the device to stop interference) and it may be necessary to wire the coil correctly according to the car polarity, most automotive relays do not have this feature.
Mount the relay near the new fuse box (it could be mounted under the same screws as the fuse box if space permits). Wire one side of the coil to the car body or 'earth', the other side of the coil should then be fed from the old fuse box where the white wires connect. These is the feed from the ignition switch and will mean the relay is energised when the key is on. Run a wire from the new fuse box Live feed to the normally 'off' contact on the relay and then from the 'center' contact to the new fuse box. (using the contacts like this mean there will be no live terminal on the relay when it is off and so is much safer) The switched accessory can then be be fed from the fused side of the fuse box
Rob
Cars: Lizzy 1970 Morris Minor Traveller and Noah 1969 Morris Mini Traveller
Cars: Lizzy 1970 Morris Minor Traveller and Noah 1969 Morris Mini Traveller
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GeorgeHurst
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GeorgeHurst
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whenisayjump
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Run a wire from the new fuse box Live feed to the normally 'off' contact on the relay and then from the 'center' contact to the new fuse box. (using the contacts like this mean there will be no live terminal on the relay when it is off and so is much safer)
Can I ask how is this safer? I'm not saying it isn't, I was just trying to follow it in my head... which can sometimes hurt
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IslipMinor
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I don't understand this either! Agree a relay should be used to relieve the load on the ignition switch, but where is the supply to the new fuse box coming from?Run a wire from the new fuse box Live feed to the normally 'off' contact on the relay and then from the 'center' contact to the new fuse box. (using the contacts like this mean there will be no live terminal on the relay when it is off and so is much safer) The switched accessory can then be be fed from the fused side of the fuse box
Richard
