Fast blinkers

[Bryan Dees]

Ok so I put new headlights in today. Installed all new headlight bulbs, blinker bulbs, running lights, and corner marker bulbs. Blinkers blink fast like there is a bulb out, but there isn’t, with the running lights on, the blinkers light up as well. With headlights on, all the bulbs on the front light up.

Any ideas? Keep in mind I just got this truck and started working on it, all of the blinkers and running lights were missing.

Thanks!

 

[GarrettGmc]

Only time I had that happen was after I installed leds, so I had to swap out the relay. Cnt remember exactly but it had to do with the amount of power that the bulbs drew in relation to weather they're slow or fast.

 

[Oldblue98]

Ok so I put new headlights in today. Installed all new headlight bulbs, blinker bulbs, running lights, and corner marker bulbs. Blinkers blink fast like there is a bulb out, but there isn’t, with the running lights on, the blinkers light up as well. With headlights on, all the bulbs on the front light up.

Any ideas? Keep in mind I just got this truck and started working on it, all of the blinkers and running lights were missing.

Thanks!

Mine light up same as you describe, maybe a flasher relay is weak or faulty with the fast flash !? Compared to my 06 Sierra the 98 sierra flashs kind of fast on mine as well ?

 

[Bryan Dees]

Thanks Garrett. I think I have an electrical issue. It is a MarkIII truck with those crappy interior lights. I have removed all of those and I’m thinking the electrical system doesn’t like it.

 

[Bryan Dees]

Mine light up same as you describe, maybe a flasher relay is weak or faulty with the fast flash !? Compared to my 06 Sierra the 98 sierra flashs kind of fast on mine as well ?

I didn’t think about the flasher relay. Now I want to turn the emergency flashers on and see how fast they flash.

 

[89RCLB]

A heavy duty flasher will most likely resolve the fast flash issue.

 

[ima93chevyguy]

+1 on trying the flasher, might be busted.

If that doesn't work you might check into the ground that's in the harness for the parking lights, mine was pretty nasty and I cleaned it up. It's toward the passenger side in the harness with all the light wires in it. Wouldn't hurt to check all your grounds while you're at it.

 

[bsn1989]

Likely a bad faulty flasher. You could get an electronic flasher and that would future proof your system for LEDs if you went down that road.

 

[Bryan Dees]

Thanks for all the info, I am going to buy a new flasher relay and see if that fixes the issue.

 

[Bryan Dees]

A heavy duty flasher will most likely resolve the fast flash issue.

Purchased a heavy duty flasher today, went to the parking lot and installed it, soon as I turned the key on, the blinker fuse blew. Took it back inside, got the factory replacement and a new fuse, installed both, fast blinker issue resolved.

Thanks for all the input!