Wiring Diagram - Comments Please

[baz-r]

the way i see it is looks like it all would work ok but

seem to notice some of your neg switching circuits are back to front
like hand brake switch.
ie. the feed is live from the ign on sw to the bulb (live all the time) and the h/brake switch earths the bulb completeing the circuit as the switch (earth switched) will only have one wire and saves exsess wiring.
bit like a oil pressure swith say.

this is done because it makes the system fail safe as most of the wiring would be on the neg side and if the insulation was damaged it would make the it go to the warning state.

dont think you need a relay for the horn as most horns are earth switched but thats up to you just copy how the orignal car did it if your not sure

you could use double gang relays say for your headlights (one coil two switchs) and fuse the feed side of the relay

you need to protect the battery side of battery by moving your fuses or by fitting a master fuse i have seen a few cars catch fire! buy poor wiring protection the closer to the battery is always better would be a shame to put all the time and money into your roadster . could even burn the garage/house down

the diode for the charge lamp is this not coverd buy the one in already in the alternator? i would need to check whats fitted

thats my take on it any way

[davidimurray]

Thanks for the comments and taking the time to look over the diagrams..

TwinTurbo - The charge light diode confused me for a while and took a few attempts to get right - when I work out which one to use I will add the part number. For the alternator feed I was planning to wire it back to the battery directly. Effectively the circuit would be connected as my diagram -but the physical wiring would be different. I will update the diagram to make it clearer that a dedicated cable should be used.

Ginge - glad I can be some help Electrics seem to be one of the areas that isn't documented very well so I thought I would see if I could change that! Once the final diagram is complete feel free to add it as a sticky to the forum.

baz-r - well spotted on the neg switched circuits - must have been asleep when I did those - will correct them and repost. Horns seem a bit of a grey area so I've played it safe - and I figure it gives you an emergency spare in cae you breakdown I used twin fuses for a number of the light circuits so that in the event that a fuse blows, you should still have some working lights. Good idea regarding a master fuse - would you suggest putting it where I have marked in the attached pic? In the location I've shown I figure it would cover both the permanent and switched live feeds. Do you have any reccomendations for the type of fuse and rating to fit? I was thinking of something like http://www.vehicle-wiring-products.e...s/holders2.php I see the Midi fuses are 40-100Amp while the Maxi are 100-250Amp. The extra diode on the charge light is included because some people have had problems with engine run on due to the megajolt continuing to draw power from the charge light after the ignition has been switched off.

Thanks again for all your help guys - and look out for version 2 coming to a forum near you soon

[alga]

Thanks David, that's a very clear diagram. And quite usable as a PDF on those 4 pages, too!

[Bonzo]

Nice work David

I am sure that layout will be very usefull in the not too distant future

The PDF works a treat, I look forward to the completed design

[davedew]

David,

Just looking at the diagram. Very useful as I to am going to be making my own wiring loom.

One thing I did notice is that you don't have a fuse in the permenant feed for the hazard lights. I think in the original Sierra loom there is a 10a fuse in this feed.

Cheers

Dave

[davidimurray]

Hello

Here we go - the latest version (V1.1) of the diagram for comment

Modifcations are -

Inclusion of 200A master fuse
Added dedicated alternator supply
Added hazards to fused supply for horn/rad fan
Corrected handbrake/brake fluid light to correct neg switched circuit

Again guys, all comments and feedback gratefully received.

Cheers

Dave

[davedew]

David,

Your going to shoot me.

Just been looking through the IVA manual at the parking light section. I think that you need to swap your ignition switched supply for the sidelights to a permenant supply to comply with the regs.

Cheers

Dave

[davidimurray]

Your going to shoot me.

Nah - that's far to kind

Seriously though it's great to have lots of input and feedback from people - better now than in the middle of the IVA test.

On the parking lamp subject (section 30 IVA manual) - I read it as they are optional on vehicles below 6m long and 2m wide, which the roadster is. If you do have parking lamps, then you must be able to turn them on without the key in.

That would suggest we don't need them. What does everyone else think?

[davedew]

Just looked at it again. The table seems to indicate like you say that they are optional on vehicles under 6m long.

Ignore me then. I wont mind, the wife does it regularly!!

Cheers

Dave

[snapper]

Megajolt has 7.5 amp fuse also check Edis, this should be on a separate fuse.
If the Megajolt fuses or fails the Edis will provide 10 degs advance for limp home