LED rear tail lights will not work with LED flasher?

[72farmer]

I am trying to get my new LED tail lights to work with no success. The LED's would work with flasher that was in the truck. But they were real slow and would finally quit after 10 seconds or so.
I bought a Grote 44891 LED flasher and ran the wire coming out of flasher to a ground like it was supposed to be. I can't get it to do nothing at all when blinker is on. The old flasher that was pluged in to the fuse block has to be wiggled around to work. I think the spade terminals that hold flasher in the fuse block are kinda worn and not holding/connecting flasher terminals. Could that be my problem (loose connection) or could I have a bad new LED relay? How could I check the relay?