Renovating wiring loom

[cherrybeard]

Happy new year.

 

I have found quite a few breaks in the wiring loom insulation, especially to the wires going to the injectors and areas where the wires curve around components. The revealing metal core is rusty and although the wire itself hasn't broken, I can imagine that this is causing me some problems if at least high resistance to certain sensors.

So to fix, is it practical to replace lengths of wires with the same gauge wire (does it need to be heat resistant wire) or am I introducing more problems here. Not sure whether I can remove wires from their connectors and successfully insert a new wire in or whether I should cut the wire a few inches short of the connector and splice a new one in that way.

I can imagine that all escort looms are now getting on a bit what with temperature cycles and general wear so I don't think a second hand one would be of much benefit.

Has anyone dabbled with their loom themselves?

[shawdreamer]

Happy new year.

 

I have found quite a few breaks in the wiring loom insulation, especially to the wires going to the injectors and areas where the wires curve around components. The revealing metal core is rusty and although the wire itself hasn't broken, I can imagine that this is causing me some problems if at least high resistance to certain sensors.

So to fix, is it practical to replace lengths of wires with the same gauge wire (does it need to be heat resistant wire) or am I introducing more problems here. Not sure whether I can remove wires from their connectors and successfully insert a new wire in or whether I should cut the wire a few inches short of the connector and splice a new one in that way.

I can imagine that all escort looms are now getting on a bit what with temperature cycles and general wear so I don't think a second hand one would be of much benefit.

Has anyone dabbled with their loom themselves?

 

you'll find that most higher grade cabling is rated for temperatures in access of under bonnet temps but if in doubt replace the loom fabric binding that you'll need to strip away to repair the damaged areas.

 

tbh though, if the wires are damaged enough to require repair your best of replacing the entire length of wire were access allows, most ford connectors have very simple plastic lips holding the wire terminals in place within the plug itself so you can usually push them in and release the terminal which in-turn allows you to un-solder the old wire from the terminal or simply crimp on a new one were necessary.

 

If after all the your still concerned about heat damage to your new wires just get yourself some of the cheap flexi cable covering kits of ebay and enclose the lot (you'll have seen the stuff........chavs buy the shocking coloured versions in attempts to flashy up their 1.1L Corsa Engine bays, thankfully though they also come in a simple black variant)

[cherrybeard]

Happy new year.

 

I have found quite a few breaks in the wiring loom insulation, especially to the wires going to the injectors and areas where the wires curve around components. The revealing metal core is rusty and although the wire itself hasn't broken, I can imagine that this is causing me some problems if at least high resistance to certain sensors.

So to fix, is it practical to replace lengths of wires with the same gauge wire (does it need to be heat resistant wire) or am I introducing more problems here. Not sure whether I can remove wires from their connectors and successfully insert a new wire in or whether I should cut the wire a few inches short of the connector and splice a new one in that way.

I can imagine that all escort looms are now getting on a bit what with temperature cycles and general wear so I don't think a second hand one would be of much benefit.

Has anyone dabbled with their loom themselves?

 

you'll find that most higher grade cabling is rated for temperatures in access of under bonnet temps but if in doubt replace the loom fabric binding that you'll need to strip away to repair the damaged areas.

 

tbh though, if the wires are damaged enough to require repair your best of replacing the entire length of wire were access allows, most ford connectors have very simple plastic lips holding the wire terminals in place within the plug itself so you can usually push them in and release the terminal which in-turn allows you to un-solder the old wire from the terminal or simply crimp on a new one were necessary.

 

If after all the your still concerned about heat damage to your new wires just get yourself some of the cheap flexi cable covering kits of ebay and enclose the lot (you'll have seen the stuff........chavs buy the shocking coloured versions in attempts to flashy up their 1.1L Corsa Engine bays, thankfully though they also come in a simple black variant)

 

Thanks, didn't know if you needed special tools to undo the connectors to get old wires out and put new in.

What I will do then is get a replacement loom and spend some evenings checking and replacing each wire as necessary.

 

Haynes specifies that the majority of the engine harness is 0.75mm2 (cross sectional area) but doesn't say whether that is including the insulation or not. There seems to be a lot of choices for wires - thickness of insulation (thin wire / standard), number of strands, thickness and amp rating. I was hoping that 1mm2, standard (not thin insulation), 14 strand, max9amp wire would be sufficient.

[shawdreamer]

Happy new year.

 

I have found quite a few breaks in the wiring loom insulation, especially to the wires going to the injectors and areas where the wires curve around components. The revealing metal core is rusty and although the wire itself hasn't broken, I can imagine that this is causing me some problems if at least high resistance to certain sensors.

So to fix, is it practical to replace lengths of wires with the same gauge wire (does it need to be heat resistant wire) or am I introducing more problems here. Not sure whether I can remove wires from their connectors and successfully insert a new wire in or whether I should cut the wire a few inches short of the connector and splice a new one in that way.

I can imagine that all escort looms are now getting on a bit what with temperature cycles and general wear so I don't think a second hand one would be of much benefit.

Has anyone dabbled with their loom themselves?

 

you'll find that most higher grade cabling is rated for temperatures in access of under bonnet temps but if in doubt replace the loom fabric binding that you'll need to strip away to repair the damaged areas.

 

tbh though, if the wires are damaged enough to require repair your best of replacing the entire length of wire were access allows, most ford connectors have very simple plastic lips holding the wire terminals in place within the plug itself so you can usually push them in and release the terminal which in-turn allows you to un-solder the old wire from the terminal or simply crimp on a new one were necessary.

 

If after all the your still concerned about heat damage to your new wires just get yourself some of the cheap flexi cable covering kits of ebay and enclose the lot (you'll have seen the stuff........chavs buy the shocking coloured versions in attempts to flashy up their 1.1L Corsa Engine bays, thankfully though they also come in a simple black variant)

 

Thanks, didn't know if you needed special tools to undo the connectors to get old wires out and put new in.

What I will do then is get a replacement loom and spend some evenings checking and replacing each wire as necessary.

 

Haynes specifies that the majority of the engine harness is 0.75mm2 (cross sectional area) but doesn't say whether that is including the insulation or not. There seems to be a lot of choices for wires - thickness of insulation (thin wire / standard), number of strands, thickness and amp rating. I was hoping that 1mm2, standard (not thin insulation), 14 strand, max9amp wire would be sufficient.

 

For the more specific wiring thickness Id suggest you have more than one thickness available to hand while your doing the repairs as there is variance between the wires used throughout (earth wires tend to be thicker etc).

 

Few others on ere will have more knowledge base regarding exact requirements Id think.

[MikeyRS]

you need the correct tools to do this properly. you should be able to get a wiring loom repair kit from ford, which includes all common size wires used in vehicles. They come labeled so you can tell the size you need. You need the right repair kit if your splicing into a loom. Also heat shrink isnt enough, you need to use the correct repair kit that contains glue in the heatshrink, which stops any water ingress.

[cherrybeard]

Thanks for the info. I have been reading through this (toyota based info) and it appears a fairly involved job where some connectors need replacement pins and so forth so I may leave the connectors alone unless absolutely necessary and just splice/replace any broken wires.

 

I didn't know you could get heat shrink tubing with glue inside. You mean this?

 

p.s. the pdf file I linked to is fairly comprehensive concerning wiring looms and connectors and how to open them up without damaging the plastic housing, so if you are feeling nerdy, have a peek.

 

I can see a full refurb costing me more (in time) than a brand new loom from ford so I'm gonna go the slightly less desirable route and repair.

 

My plan is to:

- Check each wire along its length and splice in repair pieces where necessary

- Check each wire, end-to-end for high resistance and replace where necessary

- Clean and check all connector pins for snug fitting

- Wrap it all up

- Cross fingers I haven't missed any bad contacts in connectors

[MikeyRS]

Theres still other things to check for, on the age of a wiring loom, many become hard and bumpy in sections, mainly in curved sections, its best to check and replace if you find this.

 

Again, its also best to stagger any wiring repairs, to avoid the common error of a huge lump in the wiring loom.

 

The heat shrink with glue is part of a dealer repair kit i use.

[cherrybeard]

Theres still other things to check for, on the age of a wiring loom, many become hard and bumpy in sections, mainly in curved sections, its best to check and replace if you find this.

 

Again, its also best to stagger any wiring repairs, to avoid the common error of a huge lump in the wiring loom.

 

The heat shrink with glue is part of a dealer repair kit i use.

 

What do you mean by this mate?

 

'Again, its also best to stagger any wiring repairs, to avoid the common error of a huge lump in the wiring loom.'

 

Are you referring to the spliced joints?

[MikeyRS]

Yes, when you repair the wire, dont do a bunch altogether, depending on the layout of the loom, its best to stagger the repairs, ie cutting further down the wire on the second ones. Keeps it neat and stops a big group of repairs in one area

[cherrybeard]

I see what you mean. Many thanks. One more thing, there appears to be debate as to whether a soldered joint is welcome in the engine bay. I never had too much luck with crimped connections but maybe my crimper isn't high enough quality to get decent joints. Is there an industry standard for joining wires? I will use the glued shrink wrap to protect the joint whichever route.

[shawdreamer]

I see what you mean. Many thanks. One more thing, there appears to be debate as to whether a soldered joint is welcome in the engine bay. I never had too much luck with crimped connections but maybe my crimper isn't high enough quality to get decent joints. Is there an industry standard for joining wires? I will use the glued shrink wrap to protect the joint whichever route.

 

 

unless your placing the soldered joint bare against the exhaust manifold exit I seriously doubt you'll have any issues, imho where ever possible always use a soldered joint, crimps work but I refuse to see them as anything but a short term bodge which in all likelihood will work loose or allow moisture in when simply connecting two wires together (maybe its a different story for fitting a spade connector or like but not a simple wire end to end joint).....its just inadvisable and lazy imo.

[demented]

For straight wire to wire connections, I too always solder and like other members have stated, if a number of soldered joints are within the loom, stagger the joints along the loom to prevent a build up of joints in the one area, purely for appearance, although the loom is normally not seen, who wants it to look ugly while actually making it and wrapping with insulation tape, nothing worse in my opinion.

 

As for using solder to connect wires which fit in and around the engine, like Shawdreamer said, won't be a problem, if anything, the wire insulation would melt before the solder, that'll be a far more serious problem.

 

 

When making terminal connections, I use professional Lacar type crimp connections, the very same as used by vehicle manufactures.

 

Such tools can be purchased relatively cheaply, in region of £20-30:

 

http://www.ebay.com/itm/160809280591;jsess...0591%26_rdc%3D1

 

The actual uninsulated crimp terminals are not too expensive:

 

http://www.vehicle-wiring-products.eu/VWP-...oninsblades.php

 

I tend to only use such terminals when connecting components, switches, relay etc, otherwise I solder.

[MikeyRS]

Soldered joints become brittle if not sealed correctly.

 

Using the correct inline connectors is the most secure way, coupled with the glue heat shrink. Trying to get a pix to show the connector

 

These are used to factory standard

[demented]

Each to his own technique.

 

During 20 years of auto electrical repair, installing security system and electrical component into vehicles and electrical upgardes and repairs to my own vehicles, more often than not, all wire to wire connections being soldered, the only time I've experience brittle solder joints, has been inside the Escort Mk5/6 fuse box.

 

I'm not saying that your opinion is incorrect, I've just never experience it.

 

The only other non solder in line connector I'm aware of, is a crimped on butt splice.

[shawdreamer]

solder very very rarely becomes brittle from simple moisture (take that from a time served mechanical engineer with over 11yrs of experience with soldered fittings on water, oil and gas pipework).

 

half decent insulation tape properly applied will keep moisture out almost indefinitely but its always better working practice to use correct sized properly applied heat shrink on wire to wire connections, If moisture remains a concern even after using heat shrink I often place a smear of silicone around the ends of the shrink to deter any water ingress.