Make my own loom

[geeman]

Hi all,
Ive recently been contemplating on the thought of making my own loom from scratch, just using the existing connectors from the original sierra loom, i kno i could buy one or use my existing sierra loom, but i wondered what is involved in making my own. I have a 1.8 carb cvh, and wondered what are the minimum connections to it are actually necessary to pass the iva, ie, do i need most of the sensors on the engine. Also i plan on using the sierra Haynes diagrams to build it, but does anyone have any suggestions as to if there are more useful diagrams available to build my own loom. Also i remember reading on here somewhere that someone else had made their own loom? should i use my existing fusebox as well? Thanks :)

[geeman]

just one other thing, i know this may sound stupid, but im on a card cvh, but the digram has a hybrid ignition module, and electirc choke, does my cvh even have these? if so, do i need them?
Thanks again!!

[AshG]

i made my own loom one 10 core trailer cable to the front one to the rear job done. the only sierra bit i used was the plugs for the sierra steering column.

there are some good wiring diagrams on westfield world that will help you split the wiring down into manageable tasks

[twinturbo]

1) Haynes diagrams are pants. The official ford diagrams are the best.

2) the Engine loom is a seperate part to the body loom. Keep that in one bit. Don't get rid of any sensors. All it whould need is a +12V, and ignition live to get it running.

3) Yes you need the Module, unelss yout want to build your own ingnition system.

4) If your building your own loom then there's no point in useing the sierra fuse box.

TT

[Bonzo]

Personaly I would bin the Sierra fusebox .........A hulking great lump, full of fuses & relays that you'll never need :eek: :)

Besides the engine loom.....The rest of the wiring is very basic & will prove to be quite simple if you break it into smaller individual circuits.

As said, if you are using the CVH engine as originally fitted to the car, try to keep the engine loom in one piece & don't bin any sensors.

Multi-core wire will be your best friend if you want to keep things nice & tidy ;)

[deezee]

I used the wiring and fusebox out of my 1.8 CVH. I'm using a Megajolt ignition, so I had to make my own engine loom anyway. Stripping down, shortening and re-taping the Sierra wiring took around 6 hours shop time and around 2 hours reading the haynes manual and marking it up properly. I'm also using the Sierra stalks on the steering column and the instruments, so it made more sense.

Obviously the advantage of this is I now have a complete wiring loom, relays and fuse box, at zero cost. But the whole thing was very easy to do.

[mark]

I did a similar thing as deezee, stripped the standard cvh loom of all the excess wiring (shed loads) and binned the ignition module and all the sensors in exchange for megajolt

To be honest it took me a lttle while to get it sorted as prevously i had zero automotive wiring knowledge, but it really isnt that difficult once you get your head around the wiring diagrams. If you have the donor loom i would use it and just strip out the uneeded wires carefully

The result is a loom that cost me nothing and i aquired some new skills at the same time

[tigmatt]

does anyone have any pics of a stripped cvh loom?

cheers matt

[Jezzer99]

2) the Engine loom is a seperate part to the body loom. Keep that in one bit. Don't get rid of any sensors. All it whould need is a +12V, and ignition live to get it running.

TT

That's quite insightful... I've stripped my loom but didn't realise the engine loom could be detached. I'm sure it's obvious when the loom is stretched out, but what does the connection point for the engine loom look like?

[twinturbo]

Depends on the modle year.

Pre 90 cars have 3 plugs on the inside of the car. 3,6,9 pin.
Post 90 cars have 3 plugs behind the batery ( two oval and one square )

All Sierras should have these plugs.


If you look at,
http://www.claytune.org.uk/

Weblinks, Other resources, "Loom plugs ( granada to sierra)".

That gives most of the info on the plugs although it's intended for a slightly different audience.

TT

[AshG]

if you follow the engine loom towards the bulkhead there is a big round oval connector. detach it from there. you then need to work down from the ignition switch wires to the other half of the connector. separate all the ignition wires away from the rest then cut the rest away leaving the ignition sw ones on the connector. you then have the ignition switch wiring and the engine wiring.

that was how it was on the 1600 pinto although i would suspect the cvh will be quite similar.

edit doh twin turbo beat me to it

[twinturbo]

I must add some photos too that data...

TT

[geeman]

thanks alot all, where can i find the ford wiring diagrams?, probably me being stupid, but i cant seem to find them. Also, what you're all saying sounds like a good plan, ill keep the engine loom as one piece, and then work from there. At the moment im going through the haynes wiring diagrams highlighting all the wires and bits i do actually need, and hopefully i can put the rest together from that. What sort of a fusebox would i need to buy?

Also i don't have a huge amount of knowledge about sierra wiring, so ill probably be asking hundreds of wiring questions:o

Thanks

[twinturbo]

Sierra diagrams are rare, generaly it's DEALER technical info.

I bought mine on ebay for 89/90/91 .. had an 88 set somewhere but they are awol.

they dont come up often, but dont usualy fetch much.

Since I spend a lot of time with Sierras they are my bible.

TT

[Davey]

When my car is ready for it I will be making my own loom up to suit. 7 Core trailer cable should do for the rear lighting (I'd like to use some snazzy LED light units so current load is going to be minimal). Fuse boxes are easily available and I can get water proof multi pin plug/socket gear from Durite (I have a local supplier that I use) among others. Planning to use an Emerald ECU for the ignition and injection control which comes with its own loom. One of the items I provide and install for customers is Thatcham cert alarms and immobilisers so that side of things won't be a problem. As others have said, break it down into smaller sections and its not so difficult.

D.

[Jimmyd]

PM me your email address I can send a copy of the Sierra wiring diagram.

J

[AshG]

davey. you will need 10 core if you plan to fit a fuel sender and fuel pump. ;)

this is the set-up i did on my car it will hopefully highlight what you need on the car light/service wise. the engine loom and ignition switch gear are separate looms but have to interconnect to some degree for switched live etc. etc.

Rear wire requirements
1. Tail Lights
2. RH Ind
3. LH Ind
4. Stop Lights
5. Handbrake Light (also needs extending to front brake reservoir for fluid level warning)
6. Fog
7. Reverse
8. Fuel sender
9. Fuel Pump
10. spare or earth if you have fibre glass tub

Front Wire requirements

1&2. Dipped Beam (requires a wire for each bulb due to high current load)
3&4. Main Beam (requires a wire for each bulb due to high current load)
5. Sidelights
6. RH Ind
7. LH Ind
8. Horn
9. Rad Fan
10. Brake Light switch

another couple of little things you will need to watch out for when making your own loom

1. sidelights must work when ignition is off
2. hazards must work when ignition is off
3 full beam can only be used when the dipped beam is on! but not when sidelights are on, or if all lights are off. the exception to this is full beam flash must work in all on off scenarios other than ignition off.

when it comes to relays you only need to use them when the switch gear e.g sierra stalks/savage switches etc cant take the current load of the device. for my car i have used relays for dipped beam full beam/ hazards for the flasher and fuel pump(switched on and off by engine ecu in my case).


hope all the above helps. making your own loom for the first timer can seem very daunting but its very rewarding when it all works. The plus side is if you ever have a problem you know the system inside out so it should be easy to fix.

[Davey]

Thanks Ash, that is a help. I'm not a stranger to wiring stuff up, I've built a few motorhomes and wired them all from scratch. Electrics is a large part of what I do for a living. The reason I was going to use 7 core is I've got a dirty great big reel of the stuff doing nothing very important under my workbench.

D.

[AshG]

haha i had a reel of 7 core under my workbench too. was going to use it but electronics is my thing and to have 2 cable runs down each end of the car would have been sinful.

[Tatey]

Ash may i ask where you got the 10 core cable from? After searching ebay and google i can't seem to find anywhere.

I think I will be going down the making my own loom route as it seems like a much tidier solution compared to butchering a loom and having a scruffy looking fusebox sitting in the engine bay :p

[gingea1pom]

Here (http://www.revealcable.co.uk/acatalog/Screened_Cable.html) is the first hit from Google after typing ’10 Core Cable’

[gingea1pom]

OK,

I should apologise for trying to be smart,

That link is for computer cable; however Tow Equipe do a 13 core cable for the new trailer wiring, that should work.

[geeman]

davey. you will need 10 core if you plan to fit a fuel sender and fuel pump. ;)

this is the set-up i did on my car it will hopefully highlight what you need on the car light/service wise. the engine loom and ignition switch gear are separate looms but have to interconnect to some degree for switched live etc. etc.

Rear wire requirements
1. Tail Lights
2. RH Ind
3. LH Ind
4. Stop Lights
5. Handbrake Light (also needs extending to front brake reservoir for fluid level warning)
6. Fog
7. Reverse
8. Fuel sender
9. Fuel Pump
10. spare or earth if you have fibre glass tub

Front Wire requirements

1&2. Dipped Beam (requires a wire for each bulb due to high current load)
3&4. Main Beam (requires a wire for each bulb due to high current load)
5. Sidelights
6. RH Ind
7. LH Ind
8. Horn
9. Rad Fan
10. Brake Light switch

another couple of little things you will need to watch out for when making your own loom

1. sidelights must work when ignition is off
2. hazards must work when ignition is off
3 full beam can only be used when the dipped beam is on! but not when sidelights are on, or if all lights are off. the exception to this is full beam flash must work in all on off scenarios other than ignition off.

when it comes to relays you only need to use them when the switch gear e.g sierra stalks/savage switches etc cant take the current load of the device. for my car i have used relays for dipped beam full beam/ hazards for the flasher and fuel pump(switched on and off by engine ecu in my case).


hope all the above helps. making your own loom for the first timer can seem very daunting but its very rewarding when it all works. The plus side is if you ever have a problem you know the system inside out so it should be easy to fix.

hi ashg, thats really helpful, i just wondered are you saying that you didnt use relays for other things such as the horn, or in situations where the switch can hadle the current? Also, the extra points you mentioned at the end, are they taken care of in the original sierra wiring, as i have no recollection of what the sierra light system was like, if so, ill just stick to the sierra wiring diagrams then.

[geeman]

Also one other thing, whats the sort of current that the wire will need to manage for the full beam and dipped headlights? Thanks

[AshG]

gee man if you wire up the sierra column correctly then it will all work as described above.

you can get the 10 core cable from here

http://www.vehicle-wiring-products.eu/VWP-onlinestore/home/homepage.php

[les g]

ok thats an easy one
add upp the wattage of the bulbs that the wire /switch is feeding and
divide by 12 that will give you the amperage drawn for eg..
2 x55w headlamp bulbs and 2 x5w rears and 1x3w no plate is total 123watts
so 123w divided by 12 is a tiny bit over 10 amps
so you will need cable and switching to carry 10 amps comfortably
probably you will find 17 amp cable is an industry standard ( blue lucas terminals ) and a 15 amp fuse would be adequate for this circuit..
hope that helps
cheers les g

[AshG]

little science question for you geeman. the bulbs are 55watt you have about 13ish volts you should be able to work out the amps required from that :D

aargh les you ruined it :D

the main reason i specified a wire per bulb is due to the reduced thermal efficiency of multi core cable. where they are all bundled together tightly it makes it harder for each wire to dissipate heat under high load.

[les g]

its like Cornwall Ash
Virgins Are Rare
see i was listening .
that was on the days i bothered to go to school
cheers les g

[les g]

and if i was any good with a PC.
i would do the little triangle thingy
cheers les g

[AshG]

the 10 core cable from vwp has 9 16amp cores and one thicker 25amp core

[geeman]

Aargh, if I knew they were 55 watts each I would had known what the current would be, i feel like a bit of an idiot now:o , I'll order the wire tomorrow and hopefully gt building this week then. Thanks hugely , I wolldnt be anywhere without these forums.:)

[ozzy1]

Worth trying your local caravan dealer as they usually stock 7 core and 10 core cable.

[twinturbo]

Think These are about right from memory..

Main 55W
Dipped 55W
Side 5W
Tail 5W
Fog 21W
Brake 21W
Indic 5W
Rev 21W

Dash 5w per ilumination lamp approx.


HORN - QUITE A LOT!
Blower - QUTE A LOT TOO!
Fan - SHED LOADS!
Engine - very little
Starter - WOOOOo!!!!


:D

TT

[AshG]

my nas type indicators come with 21watt bulbs although i think it can vary depending on style of the lights.

[Superloom]

Sent you a PM. Can send you the diagrams that i sell with my kit if you wish....

[twinturbo]

Your right indicators should be 21W not 5W

TT

[jasongray5]

Morning guys, approximately how much 10 core cable did you guys need to do your loom please?
Cheers Jas

[AshG]

i got 5m i think from memory. will have a look at the receipt this afternoon to check

[jasongray5]

Cheers Ash,

Im currently thinking, run 10 core to the rear, and 2 7 cores to the front, one for each corner!:D

[baz-r]

quick note dont forget to factor in lower voltages as this will push the amps up a bit
55w/14v=3.92A running/charging
55w/12v=4.58A stoped/ok
55w/11.5v=4.78A flat!

so dont forget to uprate the cable above the duty needed!
or the smoke will leak out of your cables

when i was at collage studing auotmtive engineering/design/eletronics
the rule of thumb was to work all of this and factor it into everything
and i thort it was a compleate waste of time :rolleyes:

the idea is fine for working out fuse sizes but i would be factoring in 15-20%
above duty for cable sizes

stuf like bulbs,fuel pumps etc may well be uprated in the future

[Enoch]

You have that the wrong way round Baz - the resistance of the bulb is the constant, it's the voltage that's the variable. As voltage increases and the resistance stays the same the current increases. Therefore higher engine speeds = higher voltage = higher current. always allow for this in calculating wire ratings. In the aircraft industry we used to do that, add 50 per cent then double it :)

[alga]

Well, that's close to multiplying by pi, which is used when estimating software development ;-D

[AshG]

i worked out the rating then doubled it on everything.

[baz-r]

You have that the wrong way round Baz - the resistance of the bulb is the constant, it's the voltage that's the variable :)

doh i know. i was just thinking in the wrong wavelength again
its the night shifts you know :(

[baz-r]

here's a quick calc linkey so no thinking is required :rolleyes:

http://www.sengpielaudio.com/calculator-ohm.htm

55w bulb = 2.61 ohm at 12v

11.5v=4.41A
12v=4.58A
14v=5.34A