I have this blinker relay on the panel in front of passenger seat, it is constantly clicking while parked and plugged in. If I turn on ignition then off it will stop but after a few hours will start clicking again. No lights are flashing.
Any ideas?
The first step I would take is unplug it and find out if it is the emergency flasher or turn signal. Easier to troubleshoot once you know what circuit.
Only when plugged in? It does not look like the OEM. Maybe just replace it. Usually they only click when they have power going through them to a load (light). Power comes from the turn signal or 4way flasher and that is (in my coach) part of the smart wheel harness.
That is an electronic flasher usually used when led's won't make the mechanical one flash. I had to install one to get my turn signals to flash after changing to all led on marker and turn signals