Hey y’all I’ve upgraded my reverse lights and my brake lights. Now both turn signals are hyper flashing but the hazard are not.
how can I fix it? Do I need pair of led relays?

 

The free method is to modify your turn signal flasher. This will get you by if you only have LED's installed in the rear. This does however completely disable the fast flash feature completely which is meant to inform you of when a bulb is out, so just check your bulbs every once in a while to make sure they're still working if you do this modification.

https://blazerforum.com/forum/lighti...-insane-71527/

However you'll run into some other random issues if you install LED's into the fronts as well. In my case, with LED's in the front AND rear, even after modifying the flasher relay, then I had NO turn signals at all. Also the turn signal indicators would stay dimly lit up at all times. The solution was to install load resistors in the circuit for the front turn signals along with the modification to the flasher relay. This made everything work perfect having LED's all the way around, and has continued to work fine for me for the last 5 or 6 years without any issues at all.

As a side note, DO NOT install the LED bulb load resistors in the rear of the Blazers, ONLY in the front and ONLY on the turn signal circuit for the light that's underneath the headlight. In the rear, the lights use the same circuit for the turn signals as they do for the brake lights. The resistors get HOT if they're put to constant power for more than a few seconds. So if you're on the brakes waiting at a red light, in a drive through, or whatever, those resistors that were meant for the turn signal function are actually getting power put to them when you're on the brakes too, and they just sit there and bake. Considering there's pretty much no where for the resistors to sit other than right behind the tail light, they're going to start melting into the wiring, the tail light itself, and in the worse case scenario could even start a fire! Keeping them only installed onto the turn signal circuit in the front ensures that they only see the momentary power of the turn signal flashing, and do not get hot enough to cause any collateral damage, and is enough load resistance within the circuit to "trick" the flasher into working normally.

 

Following because I'm curious.

I'm guessing the issue might be because the resistive load is different with the LED bulbs compared to the traditional ones. But that is just a guess.

 

Yep...LEDs draw only a fraction of the current of a normal incandescent bulb and the flasher/relay works on current draw. That is why when a bulb is burned-out, that side does not flash. When LEDs are used as replacements...there is not enough current draw and you get hyper flashing....relay is confused. Load resistors added to the turn signals draw additional current, which they give-off in heat and signals work normally.

Now I have read that an LED flasher/relay can be used to replace the original flasher/relay and no load resistors are needed. But that is different from what blazen_red_4x4's experience is...depends upon the vehicle and the LED flasher used. I have not tried an LED replacement myself. Actually in 10 yrs of owning my '02 Blazer I have not replaced a single bulb anywhere. Of course now that I have stated that all the bulbs will fail......

 

You need an EP29 LED relay. You can find them on Amazon for under 10 bucks.

I'd direct link the one I have but it's no longer available.

 

Not sure what all the hype is about hyper flashing. I installed LED bulbs at all four corners of my Ford Edge and have survived the hyper flashing for over three years. Unless it bothers you, there is no need to correct it as it doesn't hurt a thing.