2 trucks,2005 f350 and 1994 f250. 2 trailers, pontoon trailer and 24ft 14k equipment trailer. Hook the 2005 to either trailer and all functions work on both. Hook the 1994 to pontoon and all functions work. Hook the 94 to equipment trailer and all thesefunctions work great;running,hazard, brake lights. problem is turn signals are dim and fast. Disconnect trailer and truck turn signals work normally. Hook test light negative to trailer, probed truck plug turn signal and I get a bright, well spaced signal. CONFUSED?

 

Does your equipment trailer have LED lights?

 

New flasher relay, problem solved!!

 

Yeah they even sell HD flasher relays