Interior LED conversion.

[Laird Scooby]

Originally Posted by SwissXC90

These are not hardware devices running software that is known and can be modified

They are hardware devices with specific chips, often programmable gatearrays, that have very special code in them, with no operating system as you would know it from a PC

The embedded controllers are programmed by the manufacturer to have a specific function. And that function is supported by the hardware around the controller.

You would need hardware and firmware development experience at the manufacturer and all the right tools to be able to change anything

Not easy at all. Not at all.

Have you every seen hardware level code for a micro controller?
it's a different world altogether.

I'm familiar with GALs and PALs having used them in the past, at that time they were DIL packages, chances are these days they are SMD which again, is a totally different world. It's very hard (as i'm sure you know) to "reverse engineer" the functions of a GAL or PAL chip because as you rightly point out, they are burned at manufacture to provide a certain function or functions across the array.

Likewise i've seen, learned, written and used hardware level code and done my best to forget it! Primarily for the Zilog 8080 series but obviously much of that would be transferrable to others as the mnemonics tend to be almost generic, regardless of whether it's a Zilog, TI or whatever else to help the poor individual that has to program the things.
My only saving grace in that area is that i was better in machine code than BASIC although in all fairness (and honesty) that wouldn't have been difficult!

On another note, i suspect that if the manufacturers have been clever, they have used one bulb failure unit for ALL the bulbs, polled on some sort of Time Division Multiplex system, with different go/no-go values written into the software somewhere which would also "rotate" to suit whichever set of bulbs it was sampling at that particular microsecond.

All of that brings me back to the fact that unless there are certain things we know, such as the current draw of the replacement LED bulb, we're shooting sucker darts at black bears in a dark forest on a dark night wearing sunglasses.
That's the only way we can work out the shunt resistance of the ballast/load resistor to fool the CANBus into thinking it still has a filament bulb successfully.

[cpu_man]

Hi guys, I have a small issue here..

I purchased a pack of 4.7 Ohm resistors from the recommended link on this thread.

( https://www.ebay.co.uk/itm/Carbon-Fi...eLew:rk:2:pf:0 )

They arrived and I had ago at testing one, I placed the LED bulb in place, slid the resistor in place and the glow went away.

I pushed the button to turn the map light on and it lit up but the resistor smoked and popped?

I tried another and it done the same thing again, the bulbs were the right way round.

Something I am missing here???

[SwissXC90]

You needed 4.7k ohms = 4700 ohms, not 4.7ohms

k = kilo = 1000

Your resistors are 1000x too small in value and will smoke and burn out immediately

[cpu_man]

Originally Posted by SwissXC90

You needed 4.7k ohms = 4700 ohms, not 4.7ohms

k = kilo = 1000

Your resistors are 1000x too small in value and will smoke and burn out immediately

😂😂😂😂 in the words of Del Boy, rodney you plonker 😂😂😂😂

Looks like I have ordered the wrong ones 😂

[cpu_man]

Before I order 4.7k is there a better Recomened size or 4.7k the one to go for?

[SwissXC90]

Originally Posted by cpu_man

Before I order 4.7k is there a better Recomened size or 4.7k the one to go for?

At 14V a 4.7k resistor will consume 3mA of current and dissipate 0.042W of heat

A 1/4W resistor can handle 0.25W and is thus 6x larger than it need be

Even a 1/8W resistor is 3x larger than you need.

Just go for 1/4W resistors.
Common as muck.

[cpu_man]

Originally Posted by SwissXC90

At 14V a 4.7k resistor will consume 3mA of current and dissipate 0.042W of heat

A 1/4W resistor can handle 0.25W and is thus 6x larger than it need be

Even a 1/8W resistor is 3x larger than you need.

Just go for 1/4W resistors.
Common as muck.

thank you very much

[GSTheo119]

All this resistor talk seems like a lot of fuss, I installed THESE about 18months ago and they don't glow and have been totally reliable, recommended.

[Harley Dave]

Bit pricey at £5+ each aren't they?

Cheers

Dave

[Laird Scooby]

Originally Posted by Harley Dave

Bit pricey at £5+ each aren't they?

Cheers

Dave

Not really :

https://www.halfords.com/motoring/bu...ials-twin-pack

Only trouble with those is they have no resisitor to confuse the CANbus and are about as bright as a dead candle - 30Lm is about 1/4 of the brightness of the original filament bulb.

To compare like with like, you need these :

https://www.halfords.com/motoring/bu...nced-twin-pack

Only £15 for the pair!