[Unique427]

Switching from halogen to LED turn signals can introduce either a hyper-flash
or no flash/steady on condition with turn signals. The electro-mechanical
relays use load resistance from the halogens to switch on and off. LEDs
require only a fraction of power and hence produce very little load resistance.
You have (2) options here. Splice in a load resistor into each turn signal circuit
that mimics the halogen and fools the relay, or replace it with LED
compatible solid state relays. Option 2 is better and cheaper. Plus those
load resistors can get hot enough to melt plastic. You will need to replace
(2) relays. One for turn signals, the other for hazard lights. My relays
were (2) prong Tridon 552. If you have (3) prong relays.
Superbrightleds.com offers a (3) prong LED compatible relay.

1) CEC Industries LED Compatible (2) Prong Relay # EF32SS-R

Misc:
After switching to LED compatible relays, if you still experience a
no flash/steady on condition, the relay socket was reverse wired. Old
electro-mechanical relays are not polarity sensitive and hence the
technician who wired it did not care to check. No worries. Easily
corrected with a relay polarity adapter. The CEC Industries EF32SS-R
plugs into the adapter and together they plug into the relay socket.
If you have hazard flashers that relay may or may not need an adapter as well.

1) United Pacific Relay Polarity Adapter # 90650A

You can also create pigtail wires that go from relay into the wired socket.
Remember to cross connect both leads to correct polarity.

The above resolution will address almost every no flash issue using LED's.