Weird turn signal C5 X7 1.6hdi 2009

[martinhloevsal]

Hi!
New here, looking to see of anyone else has experienced this:

After mistakenly leaving the cover of my trailer electrical connection open for a 20 minute drive, my turn signals are going rapidly, almost twice as fast as usual. This has been a consistent condition for the last year, EXCEPT when i connect a trailer. Then everything is fine and back to normal speed. I have cleaned from the front and rear of the connection with electrical cleaner, really drowned it, everything looks OK inside the connection, but the condition of the turn signals stay the same.

Well, I have gotten used to it, but I'm going to sell my car this summer ( ), and i think it will be a good idea to get it fixed before then.

All the turn signal bulbs are fine, so i think the fault traces back to the trailer connection, but i wanna check if anyone have some other ideas or even experienced the same.

Cheers, hope you all are safe in these times!

[GiveMeABreak]

Hi and welcome.

Definitely sounds like a short somewhere. The sort of rapid flashing you would get if a bulb blew or some under-par LEDs were fitted where they weren't drawing enough current. It's possible water has penetrated the wiring sleeve from the open end and travelled elsewhere. Putting your trailer back on draws more current, so the blinking stops.

[xantia_v6]

Is your trailer wiring done with a proper harness and relay? Citroen or after-market version? If no relay is fitted, it could be that the current sensor in the BSI is damaged, or it could be that an aftermarket relay has been wired incorrectly.
Have any of the bulbs been changed from filament to LED type?
Before doing anything too expensive, it is probably worth replacing all the turn signal bulbs with new ones of the correct original specification.

[Paul-R]

In the genuine trailer socket there's a small microswitch that, when the trailer plug is inserted, informs the trailer ECU that there's now a trailer fitted. It sounds to me that this microswitch is staying switched on. Take a close look at the socket to see if there's a small piece of grit holding the plastic end in. Or maybe it's wet and needs drying out. Whatever, I think that's where you need to look at closely.