Correct wiring specification - 1996 Caterham

[TomB]

Morning, 

Whilst my fuel tank is out, Im going to tidy up the wiring at the back of my 1996 car.  Is been chopped, extended, crimped and generally messed around with for 20 odd years, so now is the time to sort it out properly. 

Starting with the LH, Im planning on fitting proper econoseal connectors for the lights, and building up a new loom for that side of the car, then connecting into the other side side to get rid of a horrible block connector where the loom has been cut prior to my ownership. Until last week I though this was standard!

When it come to wiring, I can order 1m lengths in the correct colours from Vehicle Wiring Products - the question is what kind of cable is it?     

I don't think its thin wall cable, like this http://www.vehicle-wiring-products.eu/section.php/198/1/single-core-pvc-thin-wall-cable

Im pretty sure its standard PVC cable - in which case would the link below be the right sort to buy? http://www.vehicle-wiring-products.eu/product.php/1020/8-75amp-1mm-sq-14-0-30

Thanks

[Paul Deslandes]

I would use thin wall as the insulation is much tougher (and lighter), and wrap with non adhesive loom tape.

To join to the original loom I would solder the wires together, covering each joint with heat shrink and, again, wrap with loom tape.  Soldering is not ideal but it beats a multi-pole connector or lots of individual connectors, crimped or otherwise.

Don't use standard electrical insulating tape as you'll end up with a horrible sticky mess after a time due to the adhesive reacting with the pvc insulation.

Those chocolate block connectors actually do a great job but they do look horrible and let the damp creep up inside the insulation.

I take it that you have the wiring diagram, if not I can post a link.

Best of luck

Paul

[TomB]

Hi Paul, 

Thanks for your thoughts.  I've tidied the engine bay/ front end of the wiring loom, so have used the proper loom tape before.  It makes unwrapping so much nicer and cleaner than insulation tape.  During the front end tidy up, when I need to splice into the existing loom to replace some damage, I used the metal core of a butt connector, crimped, then heat shrink put over the join.  This seems a fairly neat way of doing it.  I struggle with soldering, especially if its on the car at an awkward angle.  I end up with melted insulation, fragile looking joins and heat effected wires.  I've just not go the knack, so would probably prefer a non solder join. 

I was thinking standard PVC cable to match the stuff that already making up the rest of the loom, and also not wanting to mis-match the size of wires being joined.  Do you think it would be a problem joining thin wall to more typical auto cable? 

Cheers
Tom 

[Paul Deslandes]

Hi Tom

in many ways crimped joints are better than soldered as they are less prone to fatigue failure due to vibration, so doing as you describe is a good option.

Either standard loom cable or thin wall are okay but I like the latter because the insulation is tougher and when in a bundle it ends up less bulky.  In terms of making joints and terminations they are equally easy to use as the inner conductor is the same size for any given current rating.  Depending on what VWP sell, the thin wall conductors may also be tinned rather than bare so less likely to corrode over time.  You pays your money and makes your choice, but either will do a good job and be a lot better than the 'current' arrangement.

One trick to avoid nicking/damaging the conductors is to use the end of a hot soldering iron to melt the insulation to strip it.  Just use the tip as you would a knife to cut around the wire, obviously avoiding breathing the plastic fumes.  You used to be able to buy hot wire strippers but I haven't seen them for years and an iron does the same job.  Normal cable is more easily stripped this way than thin wall as it has a lower melting point.

Paul

[Sooty]

I agree about not using self adhesive insulation tape. Sticky mess and it wont hold in place for more than a few months. I prefer spiral wrap

[7 wonders of the world]

This makes a nice job, low tack adhesive, used by many OEM's

https://www.ebay.co.uk/itm/TESA-TAPE-51608-ADHESIVE-CLOTH-FABRIC-WIRING-LOOM-HARNESS-25mm-19mm-15mm-9mm/252275241094?_trkparms=ispr%3D1&hash=item3abcc6b086:m:m0WXjRIysBQlIn4C4n8_Ltw&enc=AQAEAAACMBPxNw%2BVj6nta7CKEs3N0qUwXVqLBuQQuomRLL4pEoL8xTiWPjVUHIqO%2Fm6WMZQoWn4HF%2Bv78HsEbJB%2BOW150fyZyESjaLT0ll7E9miK%2BPRQENnACl%2FzVX054HP4EnNCSf9z72Yt2e%2Fj9Iu4WMCw4XkWsJGJBpmB9CMkamG1xOdBBTPbQ1EAhWXXLjanb0%2FA2teDCjR%2FmwUvzb3gUwGSKRf5ayfWkv1STDNkiWe9s2k5NQ5stH2ddKxDxLAM5DsZ0tfiP7ToL%2FOH6Io3pqxFaqdxsw6lrZyuzjWqQTRXw1My4%2BjMGFnUXPOLvP%2F8%2Fzqc7qCN%2BGweumflSOctJealShcFpl%2B0VYrxpauo7RRgKKonxMiFyadOU7xgQLp1QPQCnH6uOtmXVMSuX8rVSyJAaBFjbs8WhJYAXJog2x4PcY3atV4XcFrUxUICUp%2ByemBBMJCRcJ%2F68yAKNCnsxza%2Fu5%2BM7GR0ETPQ0dOvPfSSgLhLfpZ0tooQ505enTckb9XrmgObKxVTFWKzx44Tsy1eTKxdyCOvFNUR2gblyukuAYeCdvcsD3B5Mp4HXkxHzH1KtVEmJKKUPxulOtpu7JSVJDzb5VZ9w1Wh4tbp9giqoeK5W78U0eLoxEQz3lOs6TNxt4iMxjLN4EaX7ZMlOMeiDbaSPpcj2URFydPlIxHH2BixndHX8pTAuYhp0lcYZyC5SFsqx10QNliFnMVohnVEymgrlWHO8bxsM%2B6%2BUb%2FdpVdt&checksum=2522752410941e00263fd3d4462087dae381264d3395

Make you loom up first with 1mm zip ties then tape with this afterwards clipping the zip ties off as you go.

[7 wonders of the world]

If you use the crimps get the ones with adhesive so when you shrink them it seals the joint to prevent water ingress, it also adds security as the insulation bears a portion of the load (not electrical load) on the joint should it ever be put under strain for whatever reason.