Rapid Flashing Signal Lights? Still?!

Neal96 · April 5, 2018

Hey, everyone! I’m new to the forum and I would really appreciate any help y’all could give me. About a year ago I got a 2004 Chevy Silverado and I’ve loved it so far. It’s so much better than my old Ford Ranger. However, about a couple months ago, my back left signal light went out, and as a result, my front left blinker started to naturally blink much faster. That’s obviously to be expected. I went out and got a new bulb and it fixed it right up. This week, I realized that both of my back taillights were looking very poor and needed an upgrade, so I went ahead and purchased some direct replacements. They’re the same OEM style, and fit right in. I also bought some LED bulbs to go in them, so I didn’t have to worry about the dumb halogens anymore. 3157 bulb numbers for the reverse light, the signal lights, and the brake lights. Three bulbs per housing. The new taillights came with the wiring and connectors for the junction box right next to the spare tire as well, so I went ahead and replaced it all completely. All the lights work, however the left front and rear blinkers still blink very rapidly. I don’t know why this is. I’ve tried checking the connection on the connectors, I’ve made sure the bulbs are seated good in the sockets, and I’ve even gone as far as testing different bulbs. It still seems to flash rapidly. The right side seems fine at the moment, it’s the left side that has me wanting to break me some taillights. This is the interesting part though, when I turn on the hazards, all the lights blink normally, at a regular speed. It’s only when I use the blinker that they begin to spaz. I’m just wondering if maybe anyone has any idea what’s going on here. Any suggestions? I’ve already spent about a total of $200 trying to get these things to be kind to me, so I don’t really want to drop another $300 on complete aftermarkets. I like the “upgraded stock” look.

Thanks in advance!

Neal

Tahoe2012LTZ · April 6, 2018

It's possible the LED bulbs are causing the rapid flashing? I know some models require a resistor when using LED's.

They draw less, so the electrical system thinks they are burnt.

Neal96 · April 6, 2018

4 hours ago, Tahoe2012LTZ said:

It's possible the LED bulbs are causing the rapid flashing? I know some models require a resistor when using LED's.

They draw less, so the electrical system thinks they are burnt.

Yeah, I thought about that as well, but I didn’t think that explained why only one side flashed rapidly, and the other side was normal. When the hazards are on, they’re both normal as well. Could it be the flasher relay under the dash? Maybe it’s not LED compatible or is messing up? Do you think replacing that could fix the problem?

sefiroxx · April 6, 2018

Welcome to electrical problems. Try putting the halogens back in on the left side to see if the rapid blinking stops (likelie led resistor problem) and try putting the left side leds into the right side (specific bulb problem).

If the rapid blinking doesn't move, then you might have a slight short on the right side that is allowing the leds to work without a resistor.

Better leds have a resistor built into the bulb to allow for operation with older vehicles.