Hij Andrew, I'm having problems with my Honda fr-v, 2005, similar to these: http://www.justanswer.co.uk/honda/89dwx-hi-my-left-indicator-2005-honda-frv-stuck-on.html I'm not sure what part you mean I should replace. I replaced a small black box on the back of the fuse box, measuring roughly 3" x 4" x 1" and has 3 8-pin connectors on the side that is mounted on the fuse box and one connector on the other side. Is this the part you're referring to?
I forgot to mention that the replaced box came from a donor vehicle so it could be faulty as well. Is there any way to be sure?