What's wrong with my indicators?

Pique

OK so the other day I had need to use a trailer to move some stuff and it so happened that one of the indicators on the trailer lightboard was busted so the car did the usual fast flashing as a result. The other side was fine so the normal speed flashing went on.

However since I disconnected the trailer lights, now the car indicators flash at the fast rate on both sides. All of them work too and nothing is blown. Hazard lights work at the normal speed.

I disconnected the car battery thinking that might wipe it's short term memory but that didn't work. I reattached the trailer and the behaviour was like when I first had it connected. Disconnected and it's back to fast flashing.

This is the first time I've had to use a trailer with it since I bought it. It's a 2015 Outback fwiw.

Any ideas?

Silent Shrill

Try disconnecting the indicator lights at the light unit, then start her up and use indicators, (which of course will not work at the rear). Then switch off, reconnect indicators, and try them out.

Pique

Yep no joy with that. Is there a way to reset this somehow I wonder? Removing a fuse or relay maybe?

ec_pc

did you check the electrical connector on your hitch? did any of the metal pins snap off the trailers connection and remain stuck in the cars connector?

Pique

Yep the car has the 13 pin socket with a 7 pin adapter and even removing the adapter makes no difference.

Silent Shrill

Did the trailer have led lights, or vice versa?

Pique

Not on the trailer and not in the car either afaik.

But you gave me an idea of removing the rear indicator bulbs and then replacing them to see if it knocks some sense into the ECU.

10-10-20

Did you replace any bulbs with LED replacements with the 'CANBUS' resistor in them? Might have a damaged bulb which lights up ok but the resistor is now shot.

Pique

I didn't but doesn't mean prev owner didn't.

chicorytip

Bad earth somewhere. Will need soldering. Take it to an auto-electrician.

greasepalm

Having said you disconnected battery would have been enough to reset it i would have thought.

I would also try removing bulb and if having a spare insert it as wondering is it a very bright flash with good connections or a dull flash with bad connections. + check bulbs are correctly rated .

Silent Shrill

Have you tried reconnecting the trailor with all bulbs working? It may be that the ecu sensed a blown bulb and still sees it as blown until you reconnect the trailer with both indicators working.......maybe?