another couple of things to avoid are cheap crimps and hose clips
i bought a large box of assorted crimps of the bay of evil and even using good quality ratchet crimpers it was 50/50 if the wire would pull out
what i've been doing is removing the plastic then opening up where the wire goes then crimping with a flag terminal crimper and then soldering the joint and heat shrinking
on the hose clips i got a bag from screwfix and a good half tightened then clicked as the worm drive slipped these have been replaced with terry clips and jubilee clips problem solved