shepherd564

I noticed a 3 or 4 days ago I didn't have any signal lights on my pu. I trouble shot the tail lights and decided it must the the terminal boards needed replacing. Replaced both terminal boards and put all new light bulbs in with bulb grease. Still no signal lights so I put in a new flasher. Now when I turn the signal light on it dims the brake light on that side but doesn't flash the signal light. I'm at a loss here for what is wrong. I purchased a brake light switch this afternoon but i havn't put it in yet because now I'm wondering if this could be my trailer brake controller going bad. And I'm not sure how to change the brake switch. I don't see one under the dash that looks like what I bought. Any assistance would be much appreciated.