Engine shut down - mechanical or electrical issue

Today my car shut itself down whist driving. Not a fun experience, so hopefully someone can help diagnose.
I've only done a few short trips in the time I've owned it whilst gradually restoring. JDM 3SGTE 1990.
 
The conditions were:
 
- moderate stop start traffic
- running for around 45 minutes
- approx 30 degrees, maybe more
- temp gauge in middle position
- 4th gear with minimal load, 65-70km/h down a slight hill
- revs suddenly drop and car stalls
- no smoke, steam, leaks, or other signs of trouble
 

 
After the car died, the above lights were showing with ignition on. Engine, battery, mystery battery, handbrake, oil pressure?, and possibly intercooler fan?
 
My initial thought was a dead alternator. The car has shown the orange battery looking light (bottom left) since I've owned it. The battery reads at 12.8 cold and 14.6 at idle, and is always on trickle charge so I haven't been overly concerned. Not entirely sure what the light indicates tbh. It doesn't seam to be in the manuals I've looked at so it's been on the to do list.
 
When I tried starting, it cranked fine but didn't start. Since the battery seamed ok I then thought it may be temperature related. 
 
I let it sit and cool for 30 mins and what do ya know it started fine. The only light left on was the bottom left mystery battery light as per usual. I took it easy on the drive home and gave it another 30min rest half way. It started again with no problems.
 
The radiator fans and intercooler fan were all spinning when got home. I believe that the radiator fans have a fail safe to constantly run if there's a problem with the sensor. Does the intercooler do this as well?
 
I'm wondering if there's a loose connection somewhere causing the intercooler fan to work intermittently. 
Any other ideas? Are these things known to shut down if engine bay temps get too high, and is that why aftermarket engine lid fans are popular? 
 
Probably not relevant but the car doesn't like cold starts. It takes a while to kick over which I'm guessing is due to a faulty cold start sensor or injector.  It's always started quickly once warn.
 
It's going back to the mechanics when I get around to booking for other unrelated maintenance, so it would be great if I could at least point him in the right direction.
thanks

 

^ Not to my knowledge. I think it may have had a turbo timer fitted at one stage (holes drilled on top of steering column) which can have kill-switches built in. Good idea though, I'll take a look at the ignition wiring.
Are there any OEM temp sensors that would cause engine cut out? The exhaust temp light may have come on when it died but I doubt this would communicate to the ecu. 
 
Can anyone tell me know what the orange battery light on the left is for?
EDIT: So it looks like this is a battery fluid sensor. Bit weird. I'm guessing it's not connected and highly doubt it's the cause of my issue.  

^ Do they? I've never stalled it before so I wouldn't know if they stay on or not. In that case the lights wont tell me anything. The first pic was taken after i tried cranking. When I tried again 30mins later all the lights went off after it started, except for the battery fluid light as per usual. 
 
The battery is tight and connections are solid. Is there anyway it could have lost spark momentarily? i.e. bad distributor/rotor? Sounding more like an electrical issue than a heat issue.  

I'll give it a go but there's no fault codes showing anymore except for battery fluid. When I get a chance my plan of attack will be;
- clean battery terminals and make sure its all tight
- check alternator output
- pull dash panel and steering wheel column to look for any dodgy wiring
- replace dizy cap / rotor, spark plug wires, and ignition coil
 
I'd prefer to diagnose rather than replace, but when you can get parts for less than the cost of mechanics labour, it makes sense just to replace. It's all 27 years old so probably due to for replacement anyway. 
 
 

I think I may have solved this, hopefully. 
Whilst poking around the engine bay I knocked the AFM cable loose. It looks like there is an absent retaining clip and it was just resting in place.
 
Given I've just replaced the front and rear engine mounts, it's likely that the increased rigidity shock the connecting pins loose for a split second. I pulled the cable loose whilst idling and it stalled in the same way it previously did, so I rigged up a getto cable tie strap.
 

 
I'm guessing these clips are hard to come by. Hopefully this was the cause of the issue and not just masking another problem...
 
 
 

When it will crank but not start try using a timing light on a high tension plug cable and see if the timing light is flashing which will at least indicate if it has spark.
If spark is present then it's bound to be lacking fuel.
Gain access under ashtray and check for 12 volt supply to fuel pump while engine is being cranked.
The slight misfire before stalling is indicative of an electrical interruption most likely to the fuel pump and a quick drop in fuel pressure.
Continue to be suspicious of that MAF connector too.

Have you used timing light to check for spark while cranking? Do easy stuff first.
Jumping FP and B+ will not necessarily give the answer as that removes circuit opening relay etc. from the circuit.
Disconnect fuel pump coupling under ashtray and probe with multimeter for voltage while cranking engine.
It is important to do this as the fuel pump should only receive voltage initially while key is in the cranking position.
Once the engine is running it keeps the fuel pump circuit active but if engine stalls as in an accident then the circuit is opened to prevent fuel flow. Safety feature.
You may not have a fuel pump failure but more likely a problem in the relay or wiring of the circuit.
Check easy stuff first.  Changing the fuel pump is quite straight forward but it ain't fun and you will still have the same nasty guy hiding in the circuit somewhere.

Yes. Grey coupling is fuel pump. Timing light is to just ascertain that spark is occurring during cranking. Not to check ignition timing as engine wouldn't run if it was off badly.
One thing at a time.  I have a feeling it's just one thing happening intermittently as the engine runs correctly until this problem shuts it down. That is why I have suggested to check for spark while it is playing up to rule that out first.