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        General >> Give/Need advice to/from others >> Rewiring main engine loom
        
(Message started by: tintin on Jul 1^st, 2008, 2:53pm)

Title: Rewiring main engine loom
Post by tintin on Jul 1^st, 2008, 2:53pm

ok, gonna bite the bullet and try a new engine loom on my derelict of a cossie ;D

I have the complete loom off my scrapper, and the plan is to cut out all the wiring and replace with new. Plan is to not try to solder etc onto "ends" but just replace wiring close to each junction, with extra length to allow for re-routing.

Given my lack of skills / experience with wiring, what is the easiest/most waterproof way to make the joins? Im thinking wrap together and heat shrink them.

Also, how do i know what wiring to use for each length, in terms of specification?

I feel an expensive trip to Maplins coming on ;D

Thanks in advance,

Title: Re: Rewiring main engine loom
Post by Tompion on Jul 1^st, 2008, 4:10pm

I’ve not tried them but you could have a look at these connectors:

“These terminals offer outstanding mechanical and weather resistance due to the use of a tough heat shrinkable polyamide sleeve, lined with a special hot melt adhesive around the crimp metal barrel. After crimping the terminal sleeve is heated until adhesive melts and flows filling voids and providing excellent sealing with the cable.
* Temperature rating -55C to + 125C”

http://www.vehicle-wiring-products.eu/VWP-onlinestore/terminalspreins/heatsealterms.php

Title: Re: Rewiring main engine loom
Post by tintin on Jul 1^st, 2008, 6:09pm

look great, but at 50p each i would be spending £50 on connectors, which my aberdeen blood forbids ;D still, might have to....

Title: Re: Rewiring main engine loom
Post by cossie_al on Jul 1^st, 2008, 11:03pm

Tintin,
Make sure you use heat shrink with the 'glue' lining.
Also you may want to consider protecting you new loom where it goes between the V of the engine with heat resistant sleeving.
I am no expert but I have been told that modern spec cable does the same job as older much thicker cable. if this is the case you will end up with more room to 'protect' the new loom
I am sure if you take a length of cable to maplins they will advise you well. I have always found maplin staff both knowledeable and helpfull.
Hope that is helpfull
Al

Title: Re: Rewiring main engine loom
Post by tintin on Jul 2^nd, 2008, 1:04am

hiya,

yep, plan is not to run through the V, but to put in extra length and run it somewhere more sensible (and avoid dismantling the engine!).

maplins was my first bet, but was wondering if anyone knew the specs for the wires....are they all the same?

will keep you all posted on progress

Title: Re: Rewiring main engine loom
Post by Simmo on Jul 2^nd, 2008, 6:21am

Tintin. I suggest you speak to Vehicle Wiring Products- O115 9305454. They have a comprensive catalogue, which you can access on their website which Tompion has put up. They are extremely helpful. I suggest you get their catalogue sent to you as there is a wealth of info in it and the range of materials etc is vast.

Title: Re: Rewiring main engine loom
Post by scorpio_man on Jul 2^nd, 2008, 6:49am

hi sam

this might come in handy as well...... http://www.utstrand.no/cosworth/24vEngineWiringLoomHavocRebuild/

hth

Title: Re: Rewiring main engine loom
Post by Simmo on Jul 2^nd, 2008, 7:14am

On the other hand it might frighten you to death !!!. ;D

Title: Re: Rewiring main engine loom
Post by tintin on Jul 3^rd, 2008, 6:45pm

rang them....werent very helpful.....said dunno what wiring look on our website

will this be ok?

http://www.maplin.co.uk/Module.aspx?ModuleNo=70&DOY=3m7

Title: Re: Rewiring main engine loom
Post by gozz on Jul 3^rd, 2008, 9:32pm

On the subject of engine looms,does anyone know whether or not the injector wire colour codes on our site are correct.I have done several 12v looms which are fairly simple as the injectors operate in left and right bank alternately.The 24v however is individually wired and operates in sequence as in a diesel.When I reconnected the injector plugs I did it by colour,now the thing wont run properly,
and pops and hisses.Any ideas ?
GOZZ.

Title: Re: Rewiring main engine loom
Post by tintin on Jul 4^th, 2008, 10:40pm

take a deep breath....

http://i97.photobucket.com/albums/l230/tintin74/Photo066.jpg

;D

Title: Re: Rewiring main engine loom
Post by sector-9 on Jul 4^th, 2008, 10:49pm

OP, you need to make sure the conductor cross-sectional area on the new wires is no less than that of the original ones, otherwise you could overheat them. Also you should use stranded conductors, not solid, as these are more flexible and less likely to be damaged by vibration. You shouldn't need to worry about the insulation thickness as we are only talking small volts in the engine loom which isn't likely to breach the insulation, however the insulation will need to be suitable for exposure to some heat and oil.

For connecting to the existing wiring, you'll get best results if you can strip back the original conductors to shiny copper (dull brown indicates oxidation which won't make good electrical contact). Tin the exposed conductors of both old and new wires, and put enough heat-shrink tubing to cover the joint over each new length of wire (about an inch should be enough to cover the joints and each end of the insulations). Once you've soldered in new lengths of wire and suitably insulated the joints with heat-shrink, you should wrap the whole new 'loom' with black insulating tape. This gives a more professional finish, binds the wires together and helps to protect the insulation from liquids as well as making it easier to route and secure your new loom.

Darren

Title: Re: Rewiring main engine loom
Post by sector-9 on Jul 4^th, 2008, 10:55pm

Gozz, try unplugging the camshaft sensor - this should force the ECU to fire the injectors in banked mode as per the 12v engine. See if that makes any difference. If the engine then runs fine (may be down on power a little though) then you've got one or more injectors mixed up on the same bank. If it's still running rough then you've likely got a few injectors connected to the wrong bank.

To help narrow it down which one(s) are the problem, try unplugging one spark plug lead at a time (wear thick gloves!) - you need to find which cylinder(s) makes no difference to running and those'll be the injectors you need to check.

Darren

Title: Re: Rewiring main engine loom
Post by tintin on Jul 5^th, 2008, 11:19am

;D or you could do it the tintin way ;D as i said soldering is not my thing, im going for normal crimped connectors and covering with heatshrink.

so given the wire spec you mentioned, is the trailer cable ok? it says 0.7mm and 5.5amps....it is stranded.

i hope so as i just bought 50m of the stuff ;)

Title: Re: Rewiring main engine loom
Post by sector-9 on Jul 5^th, 2008, 2:56pm

If you're gonna use crimp connectors, try gently tugging the wires apart after making the joint - it's amazing how often you think you've made a good joint then the wire falls out when you move it!

FWIW, if you're using crimp connectors, I wouldn't bother with heat-shrink tubing as the plastic insulation on the connectors should overlap the insulation on the wires. You'll also find that due to the larger diameter of the connectors, if you cut all the original wires level with each other, you'll have a large bulge in the loom because of the connectors. To avoid this, try cutting the existing wires at different points as far as possible so that the crimp connectors are staggered along the loom. Of course, you should still mummify the lot in insulating tape afterwards - even more important as moisture ingress may corrode or oxidise the connectors themselves. I still think soldering is best, especially given the vibration, etc. present; though obviously if that isn't an option to you then you'll just need to be extra careful and double-check your crimped joints...

As regarding the cable, 5A should be more than enough for the engine actuators, and positively overkill for sensors, the downside though is that your new loom is going to end up much thicker and less flexible than the original.

Darren

Title: Re: Rewiring main engine loom
Post by tintin on Jul 5^th, 2008, 5:15pm

cheers. yep, crimping i can do....

good to know on the wire spec, ta

im thinking of actually splitting the loom into 3/4 sub-looms, as im not running through the engine, so should help with size/flexibility, but will look messier under the bonnet :D will make it up when im in front of the car, in terms of routing everything.

Title: Re: Rewiring main engine loom
Post by tintin on Jul 21^st, 2008, 4:03pm

clever clogs needed !

ok, everything is going ok, but there are two "glued up" joins that i cant see how to rewire.

1) there are 4 brown wires in and 4 brown out (colour striped), crossing between the 2 main looms. colour stripes in dont match colour stripes out. how do they connect together? Are they all just joined together?

2) there is 1 purple in, and 6 purples out (going to the injectors), but two are coming out the way the 1 goes in. Again, is this just a 1 split to 6, or is there specific wires connected to specific wires?

Any help would be much appreciated