Saturday morning we did our weekly " Morgan bulb check".
Everything at the back and sides working correctly, but at the front the O/S indicator was not working.
Quick replacement of the bulb. That didn't help, so I swapped it for the known good N/S bulb. Yup, it wasn't the bulb.
Wheel off, strip the wiring, then clean the connectors right back from the back of the lamp holder back to where the two wires come out of the main loom..... The connectors look fine, but with the indicators set to flash there is no voltage...



Does anyone know what to look for next?
Could it be a fault in the wiring blocking those beloved electrons?
I've exhausted my ability to correct the fault...a nice drive to Williams next week!

try a test lamp on the feed wires from the loom ?

If the test lamp works, it is probably a dodgy/corroded connector in the back of the bulb holder....

James

If the rear o/s is not illuminated or flashing then the front won't be Peter. You need a certain electrical load collectively achieved from front and rear for the indicators to flash correctly, so measuring with what will be a high impedance voltmeter may not show 12 volts without a bulb at the front.

Suspicious are the wire colours in your pic from main chassis loom. To conform even by MMC standards the cables to offside indicators should be green/white and black. Your pic suggests two core mains cable has been used

Only thoughts are based on what I recall as your mention of Tarka being an MMC development car. Difficult to see but have the cables been extended and poor connection taped up where it exits from loom convoluted protection?

I agree re the fault symptoms of a bulb.

On the Coupe when the front wing bulb failed the remaining pair worked but went at a higher rate I believe.

Maybe a late thought for this situation but are you certain you have not had mice in there having a random lunch around the cabling ? Any signs at all.

I have two of those electric squealing things plugged in because of concern around this. We are just up the hill from the River Test and they have been seen around various back gardens etc.

Perhaps the simplest test could be to select ohms on your meter and check that you have a resistance across the two wires going to the indicator lamp holder with the lamp in place..? If not with the meter still connected try removing and replacing the bulb and see if it the reading alters...

Another posibility is to connect a 12 volt supply across the same two wires to see if the indicator lamp lights up.. and if not, with the 12 volts still connected again try removing and replacing the lamp, if it flickers and fails to stay lit during the replacement process then you may have a corroded bulb holder connection... either live, earth, or both.

Of course the earths ever tend to be the prime suspect and a cruddy lamp cap can be cleaned up with a rub of steel wool to testore connection to the metal of the lampholder where it picks up it`s earth.

Sometimes the lead contact on the centre of the lamp cruds up, or that which it connects to in the centre of the lamp holder, where a scrape with the blade of a screwdriver can restore connectivity...

Good luck Peter, you will get there.

I thought you had CANBUS light checks on the +8?

I would have thought you'd have a lamp on the dash?

Is your indicator circuit fused? I would not expect the indicators to be fused normally as they are such short usage lamps powerwise but if they are then check the fuses.

It could be the flasher relay output at fault?

Canbus works only on the stop lights and side lights, not the indicators.
I was wondering about the flasher relay, but as 5 of the 6 indicators work as normal I thought not.
Luddite has given me a check list... which I'll let Williams deal with.

Have you investigated the blue and brown cables from loom Peter? Just to reiterate this doesn't appear to be wiring that MMC would normally have sanctioned. Very easy to just cut back what looks like insulating tape and check for any botched connection.

I've ordered a new bulb holder part from Librands...then will asl Williams to install it.

Happy to drive it otherwise.... the wing repeater works, as does the rear, so according to the specialists it is most probably corrosion deep in the bulb holder.

I may take the car out, tomorrow.

When the new holder and bulb arrives I suspect I would attach it to the wires and hopefully see it flash as it should if that is the cause of the issue..?

- 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.

- 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.

You don't need to Peter. L691 lamp complete here for £26.95 delivered.

Grrrr...
I feel gouged by Morgan.....

I thought a New Year Electron Update would be appropriate.

They seem to remain in their cages, the battery needs a top up charge about once every 2 weeks, everything seems to work.
2021 was a frustrating Morgan Year, I very much hope 2023 will be better.

I very much look forward to dryer, warmer, weather......our lane resembles a river bed.

Yes, fingers crossed for a better year!

Good to read Peter, I just leave my Mog on it`s CTEK permanently trusting the float charger to keep things...err..afloat.. (-:
Quite by chance I fired up the Mog today to polish the flywheel a tad as if left for any length of time the clutch sticks...