Blinkers wont turn on its not the bulbs or fuses 01 tahoe

Did you replace the hazard/flasher/blinker relays?- they are in the fuse block usually.

This is weird, but try this: Turn on your hazard lamps and turn your steering wheel all the way left and all the way right.
Then turn on your left blinker and hold the blinker on while you turn all the way left, then right. It will click and try to turn it off but keep it held down and turned on. Then do the right blinker the same way.
I have had this problem with every GM I've ever had, something about the detent-return and the blinker relays getting reset. I'm not sure why it works, but if your flasher relays are good and your fuses,bulbs and wires are good then this is probably what will fix ya. I've had this happen often enough that I always do this first. My GM vehicles were/are all 60s to 90s models- old school, but try this before you do anything else with it it's free and only takes about 15 seconds to do. Sometimes I have to do it more than once, but eventually the detents reset and they work. Viola!
Good luck and please rate this solution if it fixes ya!

It could be the combination switch (turn signal switch). It could be the turn signal flasher. When you turn on the turn signals does the green light on the dash light and not blink? Or the green lights on the dash do not light at all? If the green lights on the dash come on but do not blink it is most likely the turn signal flasher. If nothing lights then check power into and out of the switch. If you have power into and not out of the switch then the switch is bad. If no power into then check fuses and fuse links. Check the fuses under the dash and under the hood. Hope this helps. Good luck.

have you check the turn signal flasher under dash?