Not mine, but a friend has a uk legacy gen4 facelift.
It has developed a fault where upon unlocking the hazard lights start going off, or it will be ok until 100yds down the road and then they start going off.
Car unlocks, starts and drives so I don’t think it’s an alarm/immobiliser fault.
Its been into local garage (not Subaru) but doesn’t display the fault whenever it’s been in.

I have googled it and have found a few posts where some legacy, outback and forester owners have had this happen, usually after disconnecting the battery, but I don’t think she has had it disconnected.

Ive not looked at it yet but a friend of mine says when it goes off the clicking sound comes from the steering wheel area, but if you put the hazards on physically the clicking comes from the hazard switch area. The relay for the hazards is under the steering wheel so do we think it’s a duff relay or possibly the battery is on the way out?

I would ask on uk legacy forum but I think the mods on there have slipped into a coma, I’m still waiting for account to be authorised after nearly 2 and half months!

 

I would try giving the battery an overnight charge with a CTek and see if that makes a difference.

​​​​I had an issue with a battery drain a couple of months back, which confused the Subaru alarm and one sides indicators were permanently lit.

(​​​​The drain itself was because I'd switched off the central roof light and even though the door wasn't open it was oddly taking power)