TBH £200 to sort out all the missing warning lights and get back the heater fan, the heated screen, and the MoT esential fog light, was well worth it. I've heard tales of people paying upwards of £500 for a new PCB (when they were still available from Morgan), and some buying more than one having suffered multiple failures
These tales of woe puts it all into perspective, so I'm viewing the spare gauge set, knobs, switches, clock and dash that came free with the switch panel/PCB I needed as an unexpected bonus
The PCB delete developed by Rog remains the best solution though, it's more work but ultimately cheaper as relays are inexpensive, and the PCB is completely removed. However, for me, £200 for a used improved fuse protected PCB off a late model 4/4 that I was able to fit in 1.5 hours was the best solution
It seems Morgan understood there was an issue and were starting to add PCB protection, if not a fix
Nice find Dave, what a bargain
If my memory serves me correctly this was a supplementary loom that appeared on some cars and carried additional fuses for the O/S and N/S indicator lamps. I believe their function was to protected the PCB's fragile tracks from the full 15A/20A supply when there was a fail/short/water ingress in the indicator lamps. Certainly a nice to have extra but they have caught people out when they have blown in the past as there is no circuit diagram reference to them tucked away behind the dash.
In principle it would be a simple mod to add a couple of fuses to the wires entering the 12 pin PCB connector, wires GR90 and GW86.
Not sure if these fuses would address any of the other PCB shortfalls such as the the suspected back EMF or spikes from the blower motor taking out certain components, for one.. .
For those not electrically empowered/knowledgeable, this has been an excellent but very long thread, I have despite reading several times lost my way in all the exchanges as to what is really required and the component listings to make PCB redundant.
Could I ask a favour and could you pull out the salient parts of the posting so that its easy to understand the components required and the process involved, so that you have in effect a component (possible sourcing) and assembly instruction leaflet, that would make life much easier for those of us more technically challenged. So I could hand it over to an auto electrician to build and put in my car. Last thig I want to do is fumble around this sensitive PCB and cause myself a problem that I currently don't (touch wood( have.
Many thanks in advance.
Prev '12 Plus 4 Sport OZZY '08 Roadster FELIX '06 4/4 70th LOKI '77 4/4 SEAMUS '85 4/4 MOLLY
I did post a list of the key items earlier in the thread, see below. That and the interconnect diagrams should be enough for a proper electrician to come up with a solution, I would have thought. But please don't view this as the "how to". As said before there are many ways this could be tackled or simplified using different switch types and relay configurations". It's just my attempt. Any solution will have it's pros and cons. Deejay proposed a nice push button switch alternative that was a direct replacement for the original PCB switches I believe. This would simplify the conversion negating the need for the toggle switch mounting assembly that I made up.
Originally Posted by Rog
Anybody - please check that these are correct for you, should you commit….
Heater fan switch. https://www.ebay.co.uk/itm/294842780517 Not really an auto component. It’s actually from a domestic room heater. However it appears to fit nicely. It eliminates a relay too. Time will tell how it holds up compared to the original 60's radiogram, band changer wafer switch (I did order spares). However it’s switching function is curious, at least to me. It appears to have a double wiper thingy, but works the blower ok. Take a look at my original diagram, I’ve attempted to draw it symbolically. It has no radial stop either.
It seems Morgan understood there was an issue and were starting to add PCB protection, if not a fix
Nice find Dave, what a bargain
If my memory serves me correctly this was a supplementary loom that appeared on some cars and carried additional fuses for the O/S and N/S indicator lamps. I believe their function was to protected the PCB's fragile tracks from the full 15A/20A supply when there was a fail/short/water ingress in the indicator lamps. Certainly a nice to have extra but they have caught people out when they have blown in the past as there is no circuit diagram reference to them tucked away behind the dash.
In principle it would be a simple mod to add a couple of fuses to the wires entering the 12 pin PCB connector, wires GR90 and GW86.
Not sure if these fuses would address any of the other PCB shortfalls such as the the suspected back EMF or spikes from the blower motor taking out certain components, for one.. .
Thanks Rog, at least I know where to look if the inductors fail
For now though, everything is back working, so for £200 with a spare set of gauges thrown in for free, that'll do me for now
