[Ralgha]

You mean all four signals come on at once, or just both on the left/right come on steady? All four is probably a wiring problem, two on the same side is fixed with either a new flasher relay that is designed to support LEDs, or resistors in parallel with the signals to increase the power draw. The OEM flasher relay requires a minimum amount of power running through it to make it cycle, and LEDs often don't draw enough.

Looks like those diodes are potted in a plastic housing, might be a lot of work to get those terminals out in a usable condition. One option is to jury rig the new diodes just to see if it solves your issue, and if it does to buy a new OEM diode assembly, I think they're about $40. Quite a bit more expensive though.