VX won't start, no check engine light

[Lex]

I just tried it then. No go.
What would be the thinking behind that? A problem with the transmission?

Neutral safety switch.

 

[lout]

just to clarify
this is a crank with no start condition
op has confirmed no spark

 

[Ginger Beer]

I blew a CAS a while ago, the new Triden branded one that we initially got didn't work out of the box, what brand CAS did you replace the old one with?

The CAS wiring can also sometimes fail, heat kills them

 

[Fachoo]

No check engine light. Just battery and park brake light.

All red mode lights are out when cranking, except for battery light and parking brake light.

Hmm, I have been wondering about the alternator. Have checked it, will double check it. But, surely the car would still start?

hen on reds, a soft buzzing/ringing noise coming from around alternator? Same on previous alternator.

I swapped the alternator, and it had no effect. Car won't start.
I thought you could have been on to something, as I was hearing a low buzzing/ringing coming from around the alternator when on reds. But I heard the same on the new alternator.
I'm thinking the buzzing could have something to do with the plug that goes into the regulator, but surely the regulator itself on both alternators couldn't be gone.
Then, again, I can't see that it would prevent the car from starting - unless the computer can detect a fault like that and prevent the car from starting?!

Big clue in all those quotes
I bet the 2nd alternator was 2nd hand, not brand new
I bet in both alternators the twin brushes inside black regulator were/are cactus or broken or not touching completely hence noise from motor pully shaft and most times alternator body is very hot to touch and why old battery fubar and the new battery is discharging and the dfi is not receiving any charge hence no spark at plugs.

Battery light on is the alternator/battery charging system

 

[jigz]

I blew a CAS a while ago, the new Triden branded one that we initially got didn't work out of the box, what brand CAS did you replace the old one with?

The CAS wiring can also sometimes fail, heat kills them

I didn't do the last CAS, someone else did - but turns out, they didn't. I was led to believe they had, and that the one I got in the box was the used one - just got it out, it looks brand new! Deplhi.
Oh well, just ordered a cheap eBay one too - I suppose that can be a backup.

 

[jigz]

Big clue in all those quotes
I bet the 2nd alternator was 2nd hand, not brand new
I bet in both alternators the twin brushes inside black regulator were/are cactus or broken or not touching completely hence noise from motor pully shaft and most times alternator body is very hot to touch and why old battery fubar and the new battery is discharging and the dfi is not receiving any charge hence no spark at plugs.

Battery light on is the alternator/battery charging system

You're right, the 2nd alternator is 2nd hand - I must have bad luck then.
The car isn't starting - I have recharged the battery fully with a charger a couple of times now to be sure - no change.
I can see how what you're saying might make sense with the car running, and how it might apply when the car konked out originally.
But for it not to start on a new, fully charged battery?

Which leads to me to a question I've posed earlier - is the car wired in such an unusual way that it would prevent the car from starting if the alternator broken/brushes in regulator not touching? Because traditionally, my understanding is that the battery starts the car, the alternator just charges the battery.

If what you're saying were the case though, you're suggesting that changing the regulator on the alternator might fix the problem?

 

[lout]

unless there was a dead short in the alternator
which i highly doubt
then that is not your issue
you would see the smoke
battery light will not go out until engine turns fast enough for alternator to generate electricity

 

[jigz]

have a good look at wiring to dfi module
did you use oem parts or ebay specials
do you still have the original parts
if you do ,
refit original dfi module
check the fuse under bonnet injectors/ignition 15A

Update: before tackling the job of removing the harmonic balancer to get to the crank angle sensor (I'm going to have to weld up the tool to hold it), I thought I'd have a look at the plug that connects to the DFI module (in the past, one of the female pins had splayed and wasn't making good contact). I played with that, reconnected, and it started!
Took it for a drive today, all was good. Then later, konked out again.
Does that still sound like it's the CAS (working and then not working intermittently)?

 

[lout]

Does that still sound like it's the CAS (working and then not working intermittently)?

only an oscilloscope or multimeter will answer that
could be crank sensor, dfi module or even ecu