Ignition & Fusebox

Hi L.A.B. That's great!
I want to keep it quite simple, how would I wire in the pilot light and parking option as I would like to keep it ?

Regarding "polarity sensitivity" as the Commando is positive earth does that mean I can leave them as they are:

terminal 85 is EARTH,
terminal 87 goes to ITEM to be switched on,(horn or whatever)
terminal 86 goes to the SWITCH of the item, which is fed when the
ignition is turned on.
terminal 30 goes to the battery negative terminal.

or would I have to change them around around?

You mentioned a 5 blade relay, would that mean then, say the dip beam wire from the switch going to 86 and 1 wire going from 87 to main beam and 1 from 87a to dipped beam and they would switch from one to the other by operating the Hi/lo switch?, and if the beams didn't correspond with the switch positions just change the wires 87 &87a around.

Thanks
Robert

rbt11548 said:

I want to keep it quite simple, how would I wire in the pilot light and parking option as I would like to keep it ?

Click to expand...

If you study the original switch wiring, you should see that when you switch from "Ignition" to "Ignition & Lights", you are actually switching on two circuits. The tail/pilot/instruments (Ter. 3 = Brown/Green) being one of them, and the headlamp circuit (Ter. 4 = Blue/Yellow) being the other.

T3 also serves as the "parking lights" circuit.

So ideally I'd keep both circuits rather than attempting to run all the lighting off of one switch terminal (T4 headlamp) as shown on your drawing, as then you will be able to keep the pilot and parking functions.

rbt11548 said:

Regarding "polarity sensitivity" as the Commando is positive earth does that mean I can leave them as they are:

terminal 85 is EARTH,
terminal 87 goes to ITEM to be switched on,(horn or whatever)
terminal 86 goes to the SWITCH of the item, which is fed when the
ignition is turned on.
terminal 30 goes to the battery negative terminal.

or would I have to change them around around?

Click to expand...

Yes certainly leave them as they are, my point was only to say that standard relays appear to work just the same whether connected positive or negative earth.

rbt11548 said:

You mentioned a 5 blade relay, would that mean then, say the dip beam wire from the switch going to 86 and 1 wire going from 87 to main beam and 1 from 87a to dipped beam and they would switch from one to the other by operating the Hi/lo switch?, and if the beams didn't correspond with the switch positions just change the wires 87 &87a around.

Click to expand...

30 = power (from main lighting relay?)
87 = to headlamp bulb dip/low beam. (as, in the event of a handlebar switch or wiring failure, the relay would automatically default to dip beam, - which is preferable)
87a = to main/high beam
85 = to the Hi/Lo switch main beam wire (because of the reason I gave above).
86 = Earth.

(As I said previously, the wires to relay 85 and 86 terminals could be swapped over as it doesn't seem to matter, but obviously you can't do that with the 30/87/87a in this case)

L.A.B. said:

rbt11548 said:

I want to keep it quite simple, how would I wire in the pilot light and parking option as I would like to keep it ?

Click to expand...

If you study the original switch wiring, you should see that when you switch from "Ignition" to "Ignition & Lights", you are actually switching on two circuits. The tail/pilot/instruments (Ter. 3 = Brown/Green) being one of them, and the headlamp circuit (Ter. 4 = Blue/Yellow) being the other.

T3 also serves as the "parking lights" circuit.

So ideally I'd keep both circuits rather than attempting to run all the lighting off of one switch terminal (T4 headlamp) as shown on your drawing, as then you will be able to keep the pilot and parking functions.

Click to expand...

Hi L.A.B.
Thanks for that, so if I wire in another fuse for parking, pilot etc. from position T3 as the enclosed diagram I would retain the lights? I don't think a relay would be required on the pilot circuit.

http://i411.photobucket.com/albums/pp19 ... usebox.jpg


Robert

rbt11548 said:

so if I wire in another fuse for parking, pilot etc. from position T3 as the enclosed diagram I would retain the lights?

Click to expand...

Yes, I think you've cracked it. and the right handlebar MkIII lighting switch can then be incorporated into the system.

rbt11548 said:

I don't think a relay would be required on the pilot circuit.

Click to expand...

Pilot/tail/instruments are all part of the same circuit, so it's up to you if you consider a relay to be necessary or not, personally, I wouldn't overdo the relays, otherwise you could end up with a more complex system of wiring than you started with!

Pilot/tail/instruments are all part of the same circuit, so it's up to you if you consider a relay to be necessary or not, personally, I wouldn't overdo the relays, otherwise you could end up with a more complex system of wiring than you started with![/quote]

Cheers! I think I'll give it a go, never having done extra fuses and relays before it all seems so daunting, but to wire it yourself gives a bit of satisfaction... if it works????
Reading through the site and other info on relays, they say to try and get the relay close to the switch, would you agree or put them together and run wires to where needed? I would prefer a little wiring as possible for neatness.
On a site I found this way of putting in a relay, 1 relay for all!

https://www.cyclenutz.com/electrical/fu ... ation.html

Would this work using the main ignition switch as the means of switched power?

rbt11548 said:

Reading through the site and other info on relays, they say to try and get the relay close to the switch, would you agree or put them together and run wires to where needed? I would prefer a little wiring as possible for neatness.

Click to expand...

Yes it would be ideal to keep the wiring as short as possible, but you will probably have to compromise because the fuse and relay boxes will need to be positioned in a convenient location for accessibility etc.?

rbt11548 said:

On a site I found this way of putting in a relay, 1 relay for all!

Click to expand...

You could use one relay, or many? And a single relay such as that would be useful, - but it's not the complete answer on its own.

rbt11548 said:

Would this work using the main ignition switch as the means of switched power?

Click to expand...

You'd have to wire the complete electrical system (ignition/lights etc.) to the relay from one ignition switch terminal, and then reconfigure all the switches and circuits, as you wouldn't be able to use the ignition switch to select "ignition and lights" or "parking lights" as the switch could only be used as an OFF/ON switch unless some circuits were made to operate independently of the relay?

You'd have to wire the complete electrical system (ignition/lights etc.) to the relay from one ignition switch terminal, and then reconfigure all the switches and circuits, as you wouldn't be able to use the ignition switch to select "ignition and lights" or "parking lights" as the switch could only be used as an OFF/ON switch unless some circuits were made to operate independently of the relay?[/quote]

NO!!!! sounds far, far, too complicated for me, my initial intention was to do away with the heap of connections and wires under the tank at the head steady, then I read about putting in fuses , then relays, both which do seem like good ideas, but what I don't want is what was to be a simple job turning into an epic then me giving up and using original wiring. I know I'll have to run a few more wires from the battery area, where I'm putting the fuse box, up to the headstock/headlight, but I'll use the 'thinwall' stuff Vehicle Wiring Products have.
I hope to improve certain areas of the bike, but at the same time keep it as simple as possible.
Thanks to everyone who has helped me in my wiring quest, best thing about it was no-one said "do you not know that".
Thanks again
Robert

rbt11548 said:

my initial intention was to do away with the heap of connections and wires under the tank at the head steady, then I read about putting in fuses , then relays, both which do seem like good ideas, but what I don't want is what was to be a simple job turning into an epic then me giving up and using original wiring.

Click to expand...

Adding relays to the (relatively!) high amp circuits, such horn or headlamp circuits can be worthwhile, as relays can save the puny handlebar switches from having to cope with the high current (and associated voltage losses that result from it - my own Commando's horn, -for instance, won't work properly without a relay!) but in my opinion most other circuits don't actually need a relay, and I'd consider the fitting of relays to other low-amp circuits to be an option rather than a necessity.

To add to LAB's comment, using relays can assure vital circuits receive full current. I like to use relays for headlights and horn and sometimes electronic ignition. The reason is voltage loss through bullet connectors and Lucas handle bar switches are significant. A relay is relatively insensitive to the voltage variation required to activate it, so these switches will "turn on" a relay reliably. If you measure the voltage at your headlight connector, you often will find it receives much less than 12 volts. Adding a relay in this case will noticeably make it brighter. As LAB noted, the same is true of the horn. On disc brake models the kill button is especially susceptible to corrosion affecting the voltage received at the "black box". Again a relay running from a fusebox with no intermediate connection can deliver consistent voltage.

One note on using a single SP/DT or switching relay for headlights. If you use this method you must run the feed to the lights through the key switch and then to the relay and headlights. This defeats much of the purpose of using the relay, as the keyswitch is one of the devices that can become corroded and deliver less than optimal voltage to the device. I prefer to use separate relays for low beam and high beam and run a fused circuit direct from the panel.
I feed all relay circuits from the fuse panel which is fed directly from the battery. The switching circuits are then fed from a fused circuit to the keyswitch.

Ron L said:

One note on using a single SP/DT or switching relay for headlights. If you use this method you must run the feed to the lights through the key switch and then to the relay and headlights. This defeats much of the purpose of using the relay, as the keyswitch is one of the devices that can become corroded and deliver less than optimal voltage to the device. I prefer to use separate relays for low beam and high beam and run a fused circuit direct from the panel.

I feed all relay circuits from the fuse panel which is fed directly from the battery. The switching circuits are then fed from a fused circuit to the keyswitch.

Click to expand...

Does that mean wiring 1 relay's 86 to the blue/red dip wire and the other relay's 86 to the blue/white hi beam wire as switched feeds?, and the same colour for the corresponding 87 terminals one for the hi & one for the lo beam. Also was going to run the power wire for the switch from the fusebox to the switch, is that what you mean in the last sentence in the first paragraph ?

I am not sure what you mean in the above, re feeding the fusebox direct, would that not mean that the fuse panel would be live at all times as it is fed direct from the battery ?
Do you have a drawing of this?
Thank you

Sorry I don't have a diagram. I'm horrible with programs like paint. I have a hand drawn one, but it is not in digital form.
For the headlight relay, yes, the blue/red "dip" beam wire from the handlebar goes to 86 on Relay 1 and the blue/white wire from the handlebar goes to 86 on Relay 2. The feed from the fusebox goes to 30 on Relay 1 and jumps to 30 on Relay 2. The 85 posts on each are jumpered together and earthed. The 87 of Relay 1 connects to the "dip" beam headlight connector and the 87 of Relay 2 connects to the main beam headlight connector.

The feed to the handlebar switch is run from a different fuse on the panel to the keyswitch and from the "lights" position of the keyswitch to the handlebar switch just as in the stock system.

As to your last question, yes the fuse box is live. Just as the stock wire with the fuse that runs from the battery to the key is live. If it is mounted on the battery box the connection is short and not much longer than the length of the stock single fuse. If you choose to mount this further away from the battery, then I suggest an inline fuse from the battery to the fusebox with appropriate heavier wire.

There are several possible variations of this depending on how many circuits you want to use and the design of the fuse panel. One of the neatest is the Centronics AP-1, but the cheaper plastic panels will work as well.

Ron L said:

Sorry I don't have a diagram. I'm horrible with programs like paint. I have a hand drawn one, but it is not in digital form.
For the headlight relay, yes, the blue/red "dip" beam wire from the handlebar goes to 86 on Relay 1 and the blue/white wire from the handlebar goes to 86 on Relay 2. The feed from the fusebox goes to 30 on Relay 1 and jumps to 30 on Relay 2. The 85 posts on each are jumpered together and earthed. The 87 of Relay 1 connects to the "dip" beam headlight connector and the 87 of Relay 2 connects to the main beam headlight connector.

The feed to the handlebar switch is run from a different fuse on the panel to the keyswitch and from the "lights" position of the keyswitch to the handlebar switch just as in the stock system.

As to your last question, yes the fuse box is live. Just as the stock wire with the fuse that runs from the battery to the key is live. If it is mounted on the battery box the connection is short and not much longer than the length of the stock single fuse. If you choose to mount this further away from the battery, then I suggest an inline fuse from the battery to the fusebox with appropriate heavier wire.

Click to expand...

Hi Ron , thanks what I will do is draw out a diagram, (badly), and post it for comments before I start on it .
I was also wondering, sorry but this will probably seem very very simple to you guys but..if the relay has a live switched wire going to 86 why does it need another live from the battery going to 30?... is it because when we press the switch for the item 86 +85 become energised and cause 30 + 87 to make a connection therefore giving power to the item? Don't laugh, you at the back, we all had to start somewhere!
Thanks

rbt11548 said:

I was also wondering, sorry but this will probably seem very very simple to you guys but..if the relay has a live switched wire going to 86 why does it need another live from the battery going to 30?... is it because when we press the switch for the item 86 +85 become energised and cause 30 + 87 to make a connection therefore giving power to the item?

Click to expand...

Relays are remotely controlled switches capable of handling high current far more efficiently than ordinary switches (as found on British bikes for instance) as a result, there's practically no loss of voltage across a relay, as there probably would be across an ordinary switch for instance, as switches eventually become dirty, corroded or the contacts simply wear out with use, so by using a relay, more of the available battery voltage actually gets through to the ignition, lights or horn etc..



The original switch can be used to operate a relay instead of the switch having to do the "work" itself. The switch then has an easier time, as it's only passing a low amp current in order to operate the relay.

Understanding relays: http://www.autoshop101.com/trainmodules/relays/101.html

Thanks the link was great lots of good bits in it.
I have sketched up a diagram including fusebox and relays, could I have your comments please on whether it will work or not, and is there anything that could be done better, missing or could be added.
I have left the charging side and starter stuff out of the diagram along with warning lights and lighting bulbs as the diagram is basically to make sure I have the fuses and relays correct.
diagram now changed

http://i411.photobucket.com/albums/pp19 ... IRING2.jpg



Thanks

The drawing looks pretty good! I certainly think you now know how relays work and how/why they are used.


One minor detail I did notice on your drawing, is that you have drawn a wire connection between the tail/pilot/instrument (Green/Brown) circuit and the headlamp switch, which wouldn't be entirely correct, as the original headlamp switch only selects headlamp ON/OFF (see original MkIII diagram), the pilot/tail/instrument circuit is entirely controlled from the ignition switch.

L.A.B. said:

The drawing looks pretty good! I certainly think you now know how relays work and how/why they are used.


One minor detail I did notice on your drawing, is that you have drawn a wire connection between the tail/pilot/instrument (Green/Brown) circuit and the headlamp switch, which wouldn't be entirely correct, as the original headlamp switch only selects headlamp ON/OFF (see original MkIII diagram), the pilot/tail/instrument circuit is entirely controlled from the ignition switch.

Click to expand...

Hi L.A.B., thanks for looking at my diagram, do you mean the wee green and brown wire in the bottom r/hand corner? I've had a look and you are correct, the pilot/tail and main lights should only connect when terminals 3 & 4 in the ignition switch are switched to the "light" position.
As you will notice I have wired the main battery feed through the fusebox, is this the best way to go or leave it as the original wiring with a 35amp fuse, also should I fuse the horn on it's own or leave it as it is?
Have changed the diagram.

http://i411.photobucket.com/albums/pp19 ... IRING2.jpg

rbt11548 said:

As you will notice I have wired the main battery feed through the fusebox, is this the best way to go or leave it as the original wiring with a 35amp fuse, also should I fuse the horn on it's own or leave it as it is?

Click to expand...

I see nothing wrong with putting the main fuse in the fuse box, provided that it's going to be fairly close to the battery, and that the rectifier and Zener or a voltage control box are covered by the fuse?

You could fuse the horn separately, if you wanted to, but it should be OK as it is?

Also, one thing about fuses, those old style British "35" Amp 1-¼" glass fuses are 35 Amp blow rated fuses, which would be equivalent to a 17.5 Amp (15 or 20 Amps is nearest actual equivalent) continuously rated fuse.

Most fuses available today (spade fuses etc.) are marked with their continuous rating, so you'd only have to replace the old glass 35A fuse with either a 15A or 20A spade fuse.

There is nothing wrong with the way you have set up the fuse box, but my preference is to fuse each high load circuit (relay) separately. This means the horn gets a fuse, the headlights get a fuse, and the ignition gets a fuse. Everything else can operate off a common fuse. Others may disagree, but that's my $0.02.

Ron L said:

There is nothing wrong with the way you have set up the fuse box, but my preference is to fuse each high load circuit (relay) separately. This means the horn gets a fuse, the headlights get a fuse, and the ignition gets a fuse. Everything else can operate off a common fuse. Others may disagree, but that's my $0.02.

Click to expand...

All comments most welcome!, as I said it was to judge whether I was on the right track.
I was initially going to run the main fuse as it was in the manual then I thought it might be neater to put it in the fuse box but I think I will go back to the original and run it straight from the battery via fuse to main switch, that way when I get my fuse board it would free one up to put the horn in seperate. Would you bother putting the "park" through its own fuse?, if so would you go through the fusebox? Apart from putting an inline fuse to it there is no other way you could fuse it is there?

Regarding what L.A.B. said about the glass fuses, what I could do was instead of the old glass fuse holder put a new type inline spade fuseholder in it's place, if I did that I would then change the fuse to a 20amp spade.

I take it it is all right to connect all the relay 30 terminals to the one common feed with one fuse rather than having to run a wire and fuse to the battery from each one?
Thanks Again

rbt11548 said:

I take it it is all right to connect all the relay 30 terminals to the one common feed with one fuse rather than having to run a wire and fuse to the battery from each one?

Click to expand...

Or use fused relays?: http://www.s-v-c.co.uk/prod_fusebox-relay.html see fused relay.