Starting the wiring......

[jason_l]

Hi Everyone,

Well, i have been looking at the wiring over the last few days and reading a few books on making a wiring loom from scratch. Im going to leave the engine loom to the guys at TGT but thought i would make the rest of the loom myself as it will hopefully give me a better understanding of the electrics and if anything should ever go wrong then i will know whats what better.

Plan is to start with getting the relay and fuse box mounted up under the dash and then start with wiring the horn in as the first circuit, then the rad fans and so on. Now i don't know much about electrics (im more of a mechanical man ) so will probably have a few questions as i go, including the following one.

The battery is getting mounted in the passengers footwell as i need some weight up front, and frankly there is no room for it anywhere else! Now i know that i need a big fat cable to run to the engine directly from the battery to get a nice power feed directly to it, but the plan is to have a battery cut off in the footwell to cut the power when im not using it. My question is that is it ok to run a smaller core cable to the fuse box from the battery? I can't see anyway of getting the large cable to the fusebox unless i use smaller core cable from the battery cut off switch.

Sorry if that sounds completely stupid but i am really starting from basics here  

Jason

 

[Steves2580]

Hi Jason,

Everyone's got to start some where!!

As you say "a big fat one" all the way from battery to engine, then you need to pull another live for your dash/swiches and ignition so a smaller cable is ok (not too small, or you'll have a fire).

I'll be running the big one via a cut off switch then a permanent live the the main fuse box and so on

Have you any of the old loom from the Toyota??

Steve.

P.S. Best of luck ;D

 

[jason_l]

Hi Jason,

Everyone's got to start some where!!

As you say "a big fat one" all the way from battery to engine, then you need to pull another live for your dash/swiches and ignition so a smaller cable is ok (not too small, or you'll have a fire).

I'll be running the big one via a cut off switch then a permanent live the the main fuse box and so on

Have you any of the old loom from the Toyota??

Steve.

P.S. Best of luck ;D

Thanks Steve.

I have the engine loom from the toyota but i didn't bother with keeping the interior/dash loom as i didn't see the benefit and its easier to make from scratch, even if i don't know a thing.  ;D

Im planning on running the large battery one direct to the starter motor etc but not have it go through the cut off.

The only problem is with running a smaller core cable for the dash etc is that with everthing turned on will it handle the current? Is it ok to just run a single wire from the battery cut off switch to the fuse box then ? Do i need to run a cable for each fuse or can i just connect it off the other curcuits?

Thanks again

 

[Steves2580]

Hi Jason,

Just one smaller wire will be fine, just make sure you use one that can take the amps you'll be throwing through it!
There are loads of different thicknesses of wire, each will take a different amount of amps, so one main feed to the fuse box will be ok, then split it for each of your gadgets!

Have fun working out how many amps your going to need when everything is working ;D

Steve.

 

[jason_l]

Hi Jason,

Just one smaller wire will be fine, just make sure you use one that can take the amps you'll be throwing through it!
There are loads of different thicknesses of wire, each will take a different amount of amps, so one main feed to the fuse box will be ok, then split it for each of your gadgets!

Have fun working out how many amps your going to need when everything is working ;D

Steve.

Right i think im getting this now 

The wire i have for most of the buggy is 28/35A so should be fine i guess.

 

[Steves2580]

Not quite!!

That wire only takes upto 35amps, if you have your full beam on (15amp ish) and indicate (15amp ish) then put your foot on the brakes (10amps ish), while pipping your horn (5amps+) at some git thats just cut you up! You'll have overloaded that 35amp wire and cause it to overhead and burst into flames!!!

Sorry to give you bad news, but you'll need a collection of different size and different colour wires, so you don't get mixed up!

Steve.

P.S. You'll also need different sizes of earth/ground wire!

 

[Mini Mad Max]

Can we hire you to help us? I would pay for top quality wiring help when I get to wiring my buggy haha
Max

 

[jason_l]

Not quite!!

That wire only takes upto 35amps, if you have your full beam on (15amp ish) and indicate (15amp ish) then put your foot on the brakes (10amps ish), while pipping your horn (5amps+) at some git thats just cut you up! You'll have overloaded that 35amp wire and cause it to overhead and burst into flames!!!

Sorry to give you bad news, but you'll need a collection of different size and different colour wires, so you don't get mixed up!

Steve.

P.S. You'll also need different sizes of earth/ground wire!

Sorry i didn't make myself clear  I meant i can use the 35A stuff to run to the indicators, brakes, horn etc on its own. But i will run a larger cable from the battery cut off to the fuse box to take all the current, not as large as the starter motor one but slightly smaller. Thats right isn't it?

My main worry is that the connections from the fuse box will only take a certain bore cable, as the fuse box only has crimp attachments so i can only use a certaoin thickness of wire.

Jason

 

[Steves2580]

Hi Jason,

The 35amp stuff is ample for all those applications on a single basis

Yes, you'll need to run something around the 4mm diameter to the main fuse box, then split it there ;D

I'm no expert, but I'll help if I can ;D

Steve.

 

[jason_l]

Hi Jason,

The 35amp stuff is ample for all those applications on a single basis

Yes, you'll need to run something around the 4mm diameter to the main fuse box, then split it there ;D

I'm no expert, but I'll help if I can ;D

Steve.

Thanks Steve.

I think im getting it now.......slowly.

First i need to work out what circuits i want on all the time, horn/rad fans/hazards etc and what circuits im running off the ignition, lights/dash/speedo etc

A guy at work mentioned about using a distribution block and im either going to do that or just run a few say 50 amp cables from the battery, so one would be for lights/brakes then another for horn/fans etc.

Im going to start at the weekend by hopefully mounting the fuse and relay box then wire the horn and rad fans. Think thats probably a good start. Then hopefully work out whats what with the wires from the key and indicator stalk and get that labeled up and the connector blocks changed for better versions  ;D

Im sure i will have more questions for you soon. 

 

[Steves2580]

A distribution block would be great as it would reduce the amount of wires running from the battery, the less wire the better!

Keep the questions rolling in, as I said I'm no expert but I'll help all I can

Have loads of fun!!

Steve.

 

[Phaeton]

Jason, Just check the manual, on SVA you had to have 2 methods of immobilisation, not sure about IVA. I always used to isolate the whole electrics including the starter through one of the big red switches, then just power the hazards & clock with a small feed through a fuse.

Only thing I would suggest when you do your front to back harness put some extra wires in, you never know what you may need them for.

Alan...

 

[jason_l]

Jason, Just check the manual, on SVA you had to have 2 methods of immobilisation, not sure about IVA. I always used to isolate the whole electrics including the starter through one of the big red switches, then just power the hazards & clock with a small feed through a fuse.

Only thing I would suggest when you do your front to back harness put some extra wires in, you never know what you may need them for.

Alan...

Good points Alan. I have the large battery cutoff switch (big red switch) and all the electrics will go through that, except a few key ones. and i managed to get a clifford alarm system from my bro's car so will have a full alarm imobiliser system installed anyway.

I will add a few wires to the front to back harnes now that you mention it as i will be adding more gauges and a camera system after the IVA. I would of forgotten to add the wires so im glad you mentioned that


I planned on doing the wiring today but instead i mounted the drivers seat into the car. I did get time to get a multi-meter onto the ignition/indicator stalk though and i have identified all the wires and cut off the mini conection blocks ready to fit the new water tight versions im using.

I was a bit confussed as to the ignition wires though as there seemed to be 2 circuits for the position 2 on the key? will post up the colour combo's later.

Jason
Jason

 

[Phaeton]

I'll get the wiring diagram out later, but if I remember correctly there is a live in position 1 that stays live in position 2 but drops at 3. So you can sit with radio on in position 1 no engine running & ignition circuit off, it stays live at position 2 so when driving it still works, but goes off at 3 (starter position) this is so all the power goes to starter & ignition.

Alan...

 

[jason_l]

Right, after looking at the wires coming from the ignition/stalk on saturday this is what i have.


Indicator Stalk

8 Wires in Total, colours are Purple, Purple/black, Blue, Blue/Red, Blue/White, Green/Brown, Green/White and Green/Red.

* Purple & Purple/Black - Horn Switch

* Blue & Blue/White - Lights, Main Beam (stalk in back position)
  Blue & Blue/Red - Lights, Dipped Beam (stalk in forward position)

* Green/Brown & Green/White - Right Indicator
  Green/Brown & Green/Red - Left Indicator

Now all the above is fine and i understand all of that and what wires go where, see i am learning 

Now the Ignition/Key wires.....

Ignition/Key

4 Wires in Total, Colours are White, White/Red, White/Green and Brown.

* Brown & Green/White - Position 1 on Ignition/Key

* Brown & White - Position 2 on Ignition/Key
 
* White & White/Green - Position 2 on Ignition/Key

* White & White/Red - Position 3 on Ignition/Key.

Bit more confussed with that one! I was expecting to have one 12v supply common and the other 3 wires to be the different key positions but there is not a wire that links all 3. Anyone know what should go where?

thanks,

Jason

 

[Steves2580]

Hi Jason,

Any chance of a piccy??

The size/diameter of the wire might give us a clue

Steve.

 

[jason_l]

Hi Jason,

Any chance of a piccy??

The size/diameter of the wire might give us a clue

Steve.

Damn, knew i should have taken pics  Won't be able to get pics till saturday next week as im not up there till then! From memory one/two where slightly thicker so im guessing they are the starter motor/alternator ones?

Jason

 

[jason_l]

looking at the Lucas wiring colours for older britsih cars'


Brown = Main feed from battery (unfused)

White= Ignition circuits

White/Red= Ignition switch to solenoid

White/Green = Ignition switched power for auxiliary circuits.

 

[Phaeton]

Right, after looking at the wires coming from the ignition/stalk on saturday this is what i have.


Indicator Stalk

8 Wires in Total, colours are Purple, Purple/black, Blue, Blue/Red, Blue/White, Green/Brown, Green/White and Green/Red.

* Purple & Purple/Black - Horn Switch

* Blue & Blue/White - Lights, Main Beam (stalk in back position)
   Blue & Blue/Red - Lights, Dipped Beam (stalk in forward position)

* Green/Brown & Green/White - Right Indicator
   Green/Brown & Green/Red - Left Indicator

Now all the above is fine and i understand all of that and what wires go where, see i am learning 

Jason,

Just another one which you may have considered is that the horn & headlight flash share the same permanent live feed, of course the headlight flash is not a legal requirement.

Purple is feed to Horn/Flash
Purple/Black from switch to Horn
Blue is feed to Headlights
Blue/White from switch to Dip beam
Blue/Red from switch to Full Beam & Tell-tale
Light-Green/Brown is feed for indicators
Green/Red from switch to N/S Indicator
Green/White from switch to O/S Indicator

8 Wires in all

Now the Ignition/Key wires.....

Ignition/Key

4 Wires in Total, Colours are White, White/Red, White/Green and Brown.

* Brown & Green/White - Position 1 on Ignition/Key

* Brown & White - Position 2 on Ignition/Key
   
* White & White/Green - Position 2 on Ignition/Key

* White & White/Red - Position 3 on Ignition/Key.

Bit more confussed with that one! I was expecting to have one 12v supply common and the other 3 wires to be the different key positions but there is not a wire that links all 3. Anyone know what should go where?

thanks,

Jason

Main feed directly from Starter motor on Mini does not go through a fuse but I would put one in
White/Red goes to Starter Motor or as I did Starter Motor Relay
Light-Green/White fed items that were used when engine was running, wiper motor/washer etc.
White Ignition & various other systems

HTH

Alan...

 

[jason_l]

Thanks Alan,

Thats exactly what i thought on the indicator stalk so nice to see thats all ok.

and starts to clear things up a little with the ignition wires.

Im slowly getting there!

Jason