Who knows.
One would need access to the original software, hardware and how it was programmed, to see what caused memory loss if any.
Could be other factors as motor vehicles are a very noisy environment.
I'd say an authorised service centre would have access to anything remotely like the above...
https://www.britannica.com/technology/EPROM
EPROM, in full erasable programmable read-only memory, form of computer memory that does not lose its content when the power supply is cut off and that can be erased and reused.
Assuming connection resistor and LED was in series, you forgot the voltage drop on the LED of your choice plus........
9-(say 1.7) = 7.3v on resistor
I=E/R = 7.3v/15R = 0.486A or 486mA so LED is toast .......
Then if LED shorted 9V/15R = 600mA
AND, VxA = W (or IsquaredR) so 9 x .6 = 5.4W and...
One I showed was 8 separate conductors in and out although you could almost double that.
There are many others which have more or less conductor strips.
One can also loop across sideways if required.
I can assure you, the theory behind the details of transformer construction is not hit and miss.
Unless of course you rely on instructables etc. to source the theory.
Over 1,000 books in the link below, take your pick...
Then there are the input fuses, filters, rectifier diodes, smoothing capacitors as well as all the mechanical parts, selector switches, wiring, tracks, solder joints, to get this newly formed dc to where the battery would normally connect.
Refusable means the toner can be reactivated by heat....not copies.
I'd suggest you watch a few videos on the subject as it appears you have no idea.
Inkjet is not suitable.
Unusual these days for anything to be repaired unless the fault is obvious.
Just about everything is made as throw away.
If you have zero understanding of the unit then not much hope at all.
The unit would have tolerated slight over voltage so that idea is kaput.
Fuse will blow on fault, however...
Apparently they have a gear tooth sensor on the front of the timing cover with a one wire pickup.
So I imagine the sensor to be a high resistance coil to ground.
I use the KY-003 modules from Ebay or where ever...... hall effect is the 3144.
Module has the convienience of pullup resistor and indicator LED already installed.
Essentially treat the output as open collector.
If that does not suit your application, easy enough to add a small transistor or...
Sounds like a lot of figures pulled out of thin air to try to impress.
If it is some sound system , best place to start would be Thailand.
I've seen some serious systems over there that are just plain ridiculous.
Biggest mobile unit was back in 2019 where a large tourist bus was converted. Lower...