1995 GMC Yukon Owner's Manual - Page 240

Push the button at the top of the steering column all the way down to make your front and rear turn signals flash on and off. L Your hazard warning flashers work no matter what position your key is in, and even if the key isn't in. To turn off the flashers, push the button until the first click and release. When the hazard warning flashers are on,your turn signals won't work. Other Warning Devices If you carry reflective triangles, you can set one up at the side of the road about 300 feet (100 m) behind your vehicle. Jump Starting If your battery (or batteries) has run down, you may want to use another vehicle and some jumper cables to start your vehicle. But please follow the steps below to do it safely. 5-2