When I turn my left turn signal on on my 2004 Chevy Tahoe the flashers come on, but it doesn't do it every time.

help here

https://www.google.com/search?q=2004+Chevy+classic+flasher+relay+location

And just for information OP 'Anonymous', Jeff Armer, the guy you dissed is a vehicle electronics wizard, a professional who fixes problems like your 5 days a week every week.


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Do you know what a DVOM - digital volt ohmmeter is ? How to use wiring diagrams to test electrical circuits with DVOM? Do you know how the turn signals work ? What controls them ? More then likely it's a problem with turn/hazard flasher module.

Turn Signal/Hazard Lamps
The IGN E 10 A fuse in the underhood fuse block supplies battery positive voltage to the turn signal switch assembly. Ground for the hazard switch is from G302. The FLASHER 15 A fuse in the underhood fuse block supplies battery positive voltage to the turn/hazard flasher module. When the turn signal switch is placed in either the left or right position, a voltage signal is completed from the turn signal switch to the turn/hazard flasher module. When the hazard flasher switch is activated, a ground signal is completed from the hazard switch to the turn/hazard flasher module. The turn/hazard flasher module then sends an on-off voltage signal to the appropriate turn signal lamps, or to all turn signal lamps for hazard operation through these fuses:

check the bulbs when you get rapid flash normally 1 pf the bulbs are out

logically NO. if flashers work on one side, doesn't that tell you its OK? the flasher doesn't know left or right. what do you mean be "not working"? I would suspect the turn signal switch.

there is a flasher relay for the signals and its located behind the dash on the drivers side sometimes in the lower area of the dash.when the signals are working listen to the clicking noise to narrow down the area the flasher will be in.if all else fails you can go to the library and look for a book on your car and it will have the location in it.also if you know a tech he can help you locate it as well.

The Flasher module is on the bottom left of instrument panel fuse block.

Sounds like the flasher unit to me. Normally the emergency flasher and turn signal are separate.

the most common cause of this is either a sticking 4 way flasher switch or the turn signal switch itself.

I had the same thing - it also affects the 4 way flashers.  you'll end up replacing the entire control arm (turn signal lever)
Good luck!

replace the flasher relay and the break switch