- maybe use a smear of this on the external parts of the new bulb holder assembly, when fitted....

Dielectric Grease

should help to keep the corrosion at bay

James

Wish MMC had done the same: the bulb holder is right in front of the tyre, so all the muck is hurled at it.
Dave W would devise a clever protector....
I'm not Dave.....

I would be tempted to try similar now. With a short piece of cable with bared ends, push one end doubled over into female bullet with blue cable and carefully hold other end to metal body of a bulb known to be good. Then with o/s indicators selected and flashing elsewhere, very carefully touch the bare bullet with brown lead onto centre solder blob of bulb, avoiding any short.

With luck it will flash but given the cleaning of bulb holder and connections already performed by Peter, I have a suspicion it might not. Hope I'm wrong though!

Some of the underwing bullets on my Trads were not soldered. The wire was just pushed through and bent over. All I can assume is that the wires were shortened in build.

The new light assembly arrived today from Williams: £90.00 as it is a Morgan part. As DW commented, the earth wire is not soldered into the bullet, just bent over. So I'll solder it.
Then, the wiring connectors are now joined to the loom with modern "Econoseal" connectors, not the bullets of yore! I've ordered a new female connector to join to the loom and when that arrives I can set it all up.
Should be done in time for the MOT and service at the end of the month.

This year has not been good for MOG use, just 1168 miles to date since the last MOT. I've driven the Porsche that much in the last 6 weeks.

And finally....

Wiring up Econoseal Connectors requires good light, sharp vision and the right tools.....
This is an Econoseal Connector on the new Indicator lamp...



Note....the new wires are not the same colour as on the wiring loom... green is live, black is neutral.

So I had to improvise...

First, remove the bullet connectors from the tails on the loom. One was corroded.....
Try to fit the Econoseal fitting to the tails that were left was beyond me, working under the front wheel arch, in the dark, even with a head torch and magnifying glasses. So I cheated and used a small chocolate block connector. The Econoseal I fitted with short tails.....easy on the bench.

Connected it all up and it works!!

I was VERY Happy!.

Tomorrow I'll remove the chocolate block connector and replace with crimp on tube connectors and cover with shrink wrap, tidy up the excessively long connector wire in the new light and the job is done.
I'll also strip down the old light unit and see if the area of failure is obvious!!

Good job!

It was VERY satisfying to solve the problem....it restores confidence.

Peter, hopefully you will find the problem in the old unit, if so that will hopefully restore your confidence even more, though perhaps if found to be in the light unit, confidence in the attempted repairers, less so..?

I dissected the old light unit....the bulb holder was full of water and the contact for the base of the bulb had corroded to almost nothing.

The message here is that even everything looks fine on the outside it may not be inside. Now, should I check front the N/S unit?

I should make clear that the front indicator failure was not part of the initial problem with the rear lights. They still work...and the battery remains charged, 12.3v.