The mystery of the stuck indicator lights. Not the usual...

[Nifton]

Hello everyone, I've finally got my old girl back on the road after the old classic intermittent start (pink cable). She's a 93 original release with the factory rip kit, so she gets a lot of attention from me...



I'm not clueless by any means and have so far done every fix and recondition myself, including a full dash replacement (easily the trickiest job I've done) I've also done a full rebuild of a 70s yammy, every bolt undone...

So, my current foible with my 850 is killing me;

I have the entire left side turning signals sticking, but what triggers it is the curious part. As far as indicating is concerned, the system is fine, stalk is responsive, no lights stick, the hazards work fine and do not cause the stick.
Symptom: upon locking the car, the alarm flash acknowledgement (two cycles of the hazards) sticks the left side upon the second flash.
When this has occurred, nothing above board will affect the status quo, signalling left simply gives the 'tick' half of the signalling 'tick-tock' clicking, slightly dims the dash light, with no pulse until i disengage the turn. Right turn works fine but all the while the left bank is locked. Hazard switch just turns the right lamps on, with no flashing or clicking.

Salient points:

Hazards work fine when this is not in effect. As do turn signals.

Pulling the battery does not kill the situation

Signal relay has been replaced and i have a few in stock that all test fine.

Indicator stalk has been replaced.

Current draw is as it should be.

Only setting the alarm causes this, disarming the system has never repeated the fault.

All bulbs have been replaced and the cupolas have been checked and refurbished.

I really hope someone has a few leads I can follow up on because this driving me bonkers, such a little thing makes the car unusable, just confuses everyone.

One last thing, this issue started very intermittently, and would go after an alarm signal cycle, seems to occur more readily and more permanently if she's used frequently (I.E if she was driven every other day once, it would happen after a week or so, but a day of driving with several stop will cause the fail after 3 or 4 starts, with it being a permanent fixture for the drive home).
No recent work was done during the time this started. Car has also had a new battery in the interim.

Thanks in advance