blinkers works intermittently on Chevrolet Tahoe

Try this this test:

1.) Put the vehicle in Park (or neutral)
2.) Turn on the headlights for the vehicle and activate the turn signal. If the problem is on the right, put the right signal on and vise versa.
3.) If the tail light stays light but doesnt flash, remove the trun liner
4.) Locate the rear tail light assembly and TURN IT COUNTER CLOCKWISE.
5.) With the rear socket out of the tailight, wiggle the bulb. If the bulb flashes after wiggling it, stop the signal and turn off the headlights.
6.) remove the bulb. If the socket smells like vaseline, is dirty and looks somewhat "melted", replace the socket.

In order to replace the socket, simply disconnect the connector, and connect the new socket. It is an extremely simple task that is really no harder then changing a bulb. It has fixed the problem on my 2002 Cavalier, and if you have the same problem with a 2003, there is a recall. If this fails to solve the problem, take a look at your turn signal relay or the multi function switch.

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Other possibility

Intermittent signals due to faulty hazard switch.The hazard switch needs to be replaced.As you mentioned other multiple problems with blinkers then it can be issue with faulty hazard switch.----------

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Turn signals freak out occasionally, can be "fixed" by applying pressure to hazard switch. Policy describes this as a result of a faulty hazard switch,