Hey I have a 2002 Chevy blazer I just put leds in the front side marker and turn signal the problem I’m having is when using the automatic headlights the bottom turn signals don’t flash but if I deactivate the automatic headlights and turn the lights on manually they flash like normal and on the gauge cluster the turn signal indicators are lit a little. What could be causing this? And how do I fix it?

 

I didn't encounter the "no flash" issue, but I'm aware of the dimly lit indicators in the cluster. It's because of a feature that's suppose to inform you when a light bulb is out. When a standard filament bulb burns out, the truck sees that there's no resistance there, so it knows the bulb is burnt out, so it illuminates the turn signal bulb in the cluster to inform you. With an LED installed in place of the standard incandescent bulb, because the LED has less resistance through it than the incandescent bulb does, it's as if that bulb-out warning system is confused and is telling you that "maybe a bulb is burned out?" by lighting it up dimly lol. My solution was LED load resistors on the front turn signal bulbs below the headlights. After installing them, the issues went away. It's very possible that your no-flash issue is related to the same thing.

Dropping LED bulbs in vehicles that were never initially wired for them can cause all sorts of strange issues like this. When I changed the brake lights in my wife's 2010 Elantra to LED's, the cruise control stopped working lol, who would have thought...

 

Yeah that is weird lol. I’ll try that and I think it’ll fix my no flash issue. My next question would be I have aftermarket turn signal housings that holds two bulbs will I need to wire in two of the resistors or do you think just one will be enough? Thank you.

 

Just one per side should do the trick.

 

How many ohms are the resistors that you used?

 

I'm not sure exactly. They're purpose made for LED bulb installations. They can be had at pretty much any auto parts store (nowadays anyhow, use to be the only way to get them was to order them online, but LED bulb replacement has gotten so common that places like Advance Auto and Autozone keep them in stock on the shelf by the LED bulbs now)