all my lights work but when i turn my left blinker on no blinker light on dash right blinker works hazards work only on right side

Time to inspect every light bulb look for the burnt out one. While your at it do this too,Have it read for codes, even if the check engine light is NOT on the computer will have stored information and codes. Discount auto stores will read codes for no fee. write them down.

Check your hazzard switch. Mine is having the same issue and found that it is the hazard switch, I just need to remove it and possibly clean it and hopefully it will function properly. Hope this helps.

Did u find out the problem? I'm having the same issue. 04 yukon

I found the answer to this issue. Theres a left side & a right side 10 amp fuse on the drivers side.indoor panel. Replaced the fuse and left side blinks fine again.

I have same problem with my 05 Yukon XL Denali. Installed aftermarket headlights and taillights, replaced all bulbs when i did and now all lights work, all turn signals work, 4-ways and running lights work except the 2 front right side turn signals. The small aide marker bulb wont work at all but the main turn signal on the front right will come on for running lights but wont flash. Checked all fuses and relays except flasher relay behind the dash. Tomorrow i plan on taking front end apart and checking bulbs and sockets and tracing the voltage to see where im losing signal. Doesnt make sense.