08 dodge ram 2500 flashers blink to fast after installing led blinkers even with a trailer hooked up?

You need a different Flasher Relay. I cannot tell you which one, as you have gone to a non-stock configuration. You need a relay with more resistance. The 2008 Ram doesn't have a flasher relay. The lights are controlled by the TIPM ( the computer on the underhood fuse box ). You will need to add a resistor to the led lights to bring the total resistance up to the same amount that the normal bulbs have if you want it to flash at the normal rate.