- good job Peter

I don't know if you were aware, but you can get the tube connectors (and also/alternatively the heat shrink) with a glue insert.

Waterproof Heat Shrink Butt Wire Connectors

Once you have crimped the wires ,you heat the tube/shrink as normal and the glue melts/flows and seals the joint.

It works really well and creates a proper waterproof seal....

James

Great suggestion James - I'll definitely get some of those.

I certainly wasn't aware, these look really handy. Thanks James.

I've worked on several of those Econoseal connectors Peter and there are many pitfalls although the worst is removing pins (male or female) from existing body. I now have a set of picking tools purchased on eBay one of which works perfectly for this task. Note there are YouTube videos showing how such tools allow removal of pins.

Assuming the tails on replacement bulb holder were long enough I would have assembled the male Econoseal kit you bought onto them on the bench then inserted the plug through mount hole. It worked for me when I upgraded front indicator holder to twin filament type to accommodate switchback LED's. I admit working on the loom side is more difficult though under wheel arch.

I add pins to bared cable ends after first sliding rubber plugs with barbs facing body and pins correct way around, then just crimp as soldering may leave pin too bulky. Pins are then individually inserted into body listening for the click when secure. Rubber inserts then pushed fully home and yellow pin guide inserted from other end.

When finally mating male to female body I first ensure that pins on new connector are all perfectly aligned. I then add a smear of silicon grease to body of both parts which smooths the connection - no smutty remarks please

With the benefit of hindsight I should have ordered a holder with tails supplied! As you say, they are fiddly to work on. All the You Tube videos showed the use of clever trimming and crimping tools... fine on the bench but not under the car!
The replacement light unit had massively long tails with a connector fitted, again 20/20 hindsight I should have chopped the connector off, shortened the wire and fitted a new connector: it was all a steep learning curve!
Now it is done with the long excess wire coiled up and secured with zip ties.. all very tidy and something to forget.
And yes, silicone grease made the final insertion easy and, I hope, watertight!

Peter, personally I would, then you have time to rectify at your leisure

Another useful aid when tidying wiring under wheel arches. Click image for source.

Advantage is it can be retro-fitted with everything in place. I've used it to protect brake hose as well where they rub on brake reaction bars.

Spiralwrap - such a useful product. Not just for automotive use either

I will check the N/S and if needed, clean and dry it out!
I'd rather not spend another £90,00!!

Peter, if the cable supplying the light units slopes down into the back of the light then water/damp can make it`s way past failing rubber seals and end up causing the kind of corrosion you describe If you ensure the last few inches of cable rise up to enter the rear of the lamp assembly, there may be less chance of dampness affecting the unit.