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Ok, not particularly a DTA issue but I'm sure someone can help me.

My wife has a Jap imported Daihatsu Copen 600cc , stop laughing at the back please

It is all stock and has a failed ignition coil. It has 4 x amplified COP's
I can't get hold of a new replacement and my source of 2nd hand parts can only supply a slightly different coil, it physically fits but the connecter is slightly different.
The coils have 3 pins, on the car connector pin 1 is earth, pin 2 has 5v from the ecu, pin 3 is 12v

I have set an S60 up to test on the bench and the DTA can drive an old working coil fine.
The new (2nd hand) replacement coil appears to have pins 1 and 3 swapped from photos of the wire colours from the engine it came from (600cc Copen). I can make this coil work on the DTA under test, all tests undertaken with amplified coils ticked.
With a meter on the coil I see 1ohm and a diode between the signal pin and I think the 12v.

The issue I have is that the new coil will not work on the car, what am I missing?

I could buy a coil from another type of car and make fit but from my testing there may be something odd about the way the coil is fired on the car?
I need to have a look with my oscilloscope to see what different from the car and the DTA

Anyone got an idea?

Pretty much generically for 3 wire internal ignitor coils.

A coil will have 12v power.
A coil will have an ecu trigger. This tends to be 5v to charge and 0v will fire. I have not seen a modern internal ignitor coil behave in the reverse of this.
And the coil will have a ground.

If you have tested and see 5v at any pin, that would seem strange. You would also need to have a bit of an idea of what sort of dwell time the current coils have, and what any new coil might want

Ideally yes scope both the coil trigger and current to see voltages, and also dwell time ( I guess current not essential, but could be when testing the new coil to ensure it doesn't saturate too early )

Pretty sure you cannot ohm test such coils to get anything valid from them ?

Thanks Stevie, having now found a wiring diagram I can see 2 variants of ignition system.
The One I have uses 3 wire internal ignitor coils. Appears this is rare as hens teeth.
The other type used 3 wire dumb coils with an external ignitor, the 3rd wire is used for misfire detection back to the separate ignitor unit, this is the only coil I can get in the UK and that's 2nd hand. There are some coils on ebay but are in Japan at vast expense.

I'm thinking of adding a stand alone ignition ignitor for just one coil as a low cost solution, can you see any issue with that?

I think I've been lucky not to have damaged my S60 by driving a dumb coil with external amps ticked !!!

Post a picture of the coil ? Bound to be something that could be used.

Although I guess you could use an external ignitor. But when there are so many different coil types out there, bound to be something that would fit.

But again, I'd still want to have an idea of the sort of dwell times that the system uses before choosing a coil.

Ok for any one interested, I ended up installing a Bosch 200 series coil amplifier allowing me to use standard Copen dumb coils. To prove it was all working ok I have taken traces of the original amplified coils and also the retro fitted dumb coils + Amp.
The attached shows the input signal in blue and the coil current in red. Both coils peek at around 8 amps but the dumb coils reach saturation, the coils with amps don't, these tests were only at idle, so I was not bothered about any other adjustments to dwell in action.
The scales are not the same but you can get the idea. You can see the charge time at 2.1ms for both
One interesting thing is that the standalone amp appears to stop the full 5v to the amp, it rises to 5v over the charge period. this must be making the ecu run hotter to do this?
Any way car is running fine now with 2 x dumb coils + Amp and 2 x cop with built in Amp

I'd guess it must be a heavier load than the ecu expects on that trigger, but I'd say any current would be negligible ( current clamp ? ). But equally, the 5v line would probably have a very limited power behind it as it would never be intended for a load.

With such a short dwell time, I think the red VAG pencil coils run similar short times. Quite surprising the coil is saturating well before that unless that is partly to do with the amp itself ?

Sure, it's running, hopefully it will last without any ill effects.