$60 flasher required ????

I was given a utility trailer as payment for a snowmobile. It is in nice shape except for some of the lights were broken. So, I figured since I have connections (no pun intended) in the class 8 truck parts business I'd equip the trailer with all LED lights. I bought Truck Lite LED marker and oval taillamps to replace anything that was broken. Once I had everything swapped out, I hooked up the cord to my truck to test. Everything works except the stop & turn function of the tail lamps. I checked and triple checked the wiring, made sure grounds were grounded, made sure there was 12v power from the stop/turn wire of the harness. Still nothing. I bench tested the LED tails and they function perfectly. Why don't they work in thr trailer? I contacted Truck Lite and they advised for the Fords there is a special low-amp flasher required (#92783) because the LED draw so little amps the truck does not "see" that the lamps are there?
Has anyone else run into this before?

Thanks
E.



