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The cause of this is due to the small amount of power the LED's require compared to the old style bulbs. It's called hyperflashing. It is normal when a standard bulb burns out to indicate there is an issue. In this case, the LED's draw such a small amount of power, the flasher thinks one is burned out.
One way to stop this issue is by replacing the flasher in the vehicle with an LED flasher module. They are designed for this type of bulb. You should be able to get them at any parts store.
The only other thing I can think of is a load resister kit. Basically, you are placing a resister inline to the bulb which will cause more power to be required. Thus, the flash will slow.
Let me know if this helps or if you have other questions.
Tuesday, October 1st, 2019 AT 6:11 PM