Broke the hazard switch on my Bravada when I was reinstalling the dash after a Sirius radio hardwire install. Breaking the hazard switch caused turn signal problems. In my case had to replace entire flasher/ turn signal/ cruise control assembly. GM made a hazard only replacement but I could not get the part in time as I had to drive the Bravada and needed an immediate fix.
One clue if it for the sure the hazard is if the problem is present without the ignition turned on. If the problem is not present with the ignition off, you may have want to extend your diag/ isolation.
2001 Bonneville SSEi, 219,000 miles.
Whats in my driveway:
1998 Chevy S10 4x4 ZR2, 1999 Olds Bravada, 2001 Pontiac Bonneville SSEi, 2007 Ford F-350 regular cab 2WD, 2008 BMW 335i coupe (Wife'* replacement for her Bonneville). The Bonneville is my favorite of all the cars in the driveway.