Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Gauges not working

MMC set up quite a sizable (for them) off site R&D division prior to the introduction of the CX, employing a few ex Lotus lads, they have perhaps trimmed that down ?

Many thanks Rog although dissapointed it's such a large open to the elements PCB. I really thought MMC would have learnt. Very likely the single instrument pod on the 3.7 Roadsters borrowed from the Mustang has something similar, but it's completely encased in plastic further offering support for the multiway connectors and not a fragile ribbon cable in sight.

Warranty work due to a batch of faulty components is always a nightmare for the factory parts stockists until the weakness appears and the demand for a component builds up. By then the lead time to build extraordinary stocks means delays further up the supply chain. During my 20 years in motorcycle spare part distribution I recall a situation when something like thirty tachometers for a particular model were on back order with the factory (only stockists of custom part) when typically we would have been lucky to sell one every couple of years. The unforeseen demand due to failures in early life catching everyone out, exacerbated by need for fresh batch/design from the manufacturers when it was eventually realised the whole original batch had a potential weakness hence pointless replacing like for like.

Does this have a familiar tone

I agree Richard, where’s the protection!

Considering the gauges have their own connectors, that PCB has 38 connections

Perhaps that's why the Factory were very anti tonneau cover when the CX's came out, worries over water ingress down the back of the dash ?

Another plus.....
The clock now lights up!
It was not previously lit and checking in here it seems that was the norm.
Not particularly bright and the hands are not very clear but it does light up just enough.
When the gauge problem was being fixed the dealer tried just replacing the wires that MMC sent as the fault looked like a loom multi pin connector problem.. That didn’t work with the original pcb. The new pcb was therefore fitted and everything worked.
I wonder if there was an upgrade that meant the clock lighting was then fixed?

AH! They finally sourced a new and less faulty (for the moment) PCB. That is great news. Another encouraging sign from the new owners.

However, the issue was never merely the unwise choice of PCB supplier, a vestigial hold-over from the Hard Times. It is/was the use of PCBs all together on a limited production collector car that, (if I can be forgiven a 1996 quote from Charles Morgan at the time he began supplying trads with stainless [which stain] steel bulkheads and valences). The cars "will last the lifetime of the owner". PCBs are one of the newer sad habit of current mass automobile production the MMC community does NOT not need. BTW, they cost pennies to produce after the first. How much was the charge for the new one?

Even the highest quality PCBs cancel out the wisdom of multiple-fuse fuse boxes and the brilliant British invention of coded wire colors. They eliminate a huge amount of manufacturer man-hours while shifting an immensely heavy burden onto owners..without any compensation for the large manufacturing costs saved. Such things became a characteristic of the MMC Production department during the "Hard Times".

Fixing something that is, in principle, bad for this genre of car, merely delays the inevitable and sets up additional frustration for the future. They threaten the longevity of a car made to "last forever". And I prefer mogging with my wife than a IT expert in her place. Once PCBs are eliminated, the cars so equipped will be worth more IMHO. They add NOTHING of interest to mechanics and owners.

Sorry but someone had to point this out as clearly as possible. My first loyalty is to the cars..and then the owners.

gmg

The car is a 2023 Plus Four, still under warranty. No cost incurred.
These days cars seem to be built around electronics. There are so many systems that require a pcb to manage them. Many of these are linked to modern day emissions/eco control and feed back data to the ecu. Others are for other systems that are not actually a necessity. They pander to marketing the car as full of “desirable” tech. I have a Kia with electric handbrake and an auto hold to make hill starts easy. The latter I find ok. The former...not so. It is linked to the driver’s seatbelt to keep it on unless the seatbelt is in place. That would be ok for two types of person. The numpty who doesn’t want a seatbelt and the forgetful person. Add in the myriad other systems like electric seat adjusters with memory settings for different drivers. No wonder the shortage of pcb’s during Covid/Suez canal blockage interrupted car production when the Far East was the supplier.

With respect, one of the things I have learned after so many years of repair questions & answers, is that the only thing certain with a failed component replacement is that that same part will fail again. This is fine with the average car that will be in some break-up yard before long, but not a car you expect will last a century. If you want your Morgan to be reliable forever, you must have a different repair philosophy.


PCBs are totally unnecessary to the function of your car. They are, as explained, even prejudicial. They merely save time for manufacturers..what economists have been calling "hidden inflation", while making the car less reliable and repairable for unaware owners. As the Community has already seen, at some point in time, your PCB will be unobtainable, either for long periods or forever. And during the period they do work they cancel out most of the brilliant British electrical diagnosis ingenuity added to the world automobile art for over a century, while adding to reliability risks. Their forced replacement is inevitable in cars which are supposed to be treasured for generations. The question is merely whether an owner does it now, when the use of every wire to the PCB is known, or chooses to live in hope, leaving the task to some future owner without the same knowledge. BTW, the way, the world center of aftermarket goodies always optional in chrome sells dozens of coded wiring kit types, all pre-attached to muchly upgraded fuseboxes. (which are likely unnecessary for the the post-2004 MMC boxe). I plan to re-wire my non-PCB Morgan next summer. After 23 years, my MMC special, has not stood the test of time, with the fisebox internally damaged and the cheaper wiring and connectors showing their usage. The Rover/LR EI 30 year old wiring loom is fully intact, but the MMC stuff did not hold up as well.

I sympathize with you. I am reminded of the time my Municipality required me to upgrade my septic system when I rebuilt our very remote home 30 years ago. 15,000 quid! I cannot think of a single way that changed my lifestyle or gave us greater joy! But it was necessary.

gmg

Unless I am missing something by not seeing the wiring harness the speedo, tacho, and clock, should not be affected by the PCB in as much as they have their own wiring connectors. The PCB seems to be a mounting panel for the various pushbuttons and fan, and heater controls. In fact there are 2 PCBs one piggybacked on the other. It is also difficult to comment much without seeing what components are mounted on the other side however in general terms I suspect the components are very simple resisters, capacitors, and diodes, most if not all surface mounted. If this is the case they would all be very easilly replaced, if necessary by a competent technician.

It is more likely that problems may occur in seeking replacement for the mechanical components in the future.

A well buit and designed circuit board should last a very long time as long as you don't ask it to accept unreasonable peak loads. This, and a poor design of the heater fan connection in the 2012 Plus 4 is what led to its replacement with a more traditional system. If the heater fan had been wire/controlled differently it probably would have coped.

In the case of the CX PlusFour it really looks to me like a logical solution to bringing all the electrical connections to the multiple connector on the dash wiring loom. When all is said and done it has to be much better than a rat's nest of wires.

I also would not worry too much about it not being covered. A cover is only going to keep curious fingers away from it and the circuit itself is coated to protect it. Unless it has been done on the very cheap any exposed metal should be plated with a corrosion resitant layer, even gold.

As for the Engine Control Unit and any other control units that is going to be more difficult in the far future as some components may be impossible to find if they need to be replaced, but that is another story.