1999 Chevrolet Express Van Owner's Manual - Page 101

yellowblue CAUTION: It can be dangerous to drive with the rear swing-out windows or rear door(s) open because carbon monoxide (CO) gas can come into your vehicle. You can't see or smell CO. It can cause unconsciousness and even death. If you must drive with the rear swing-out windows or rear door(s) open or if electrical wiring or other cable connections must pass through the seal between the body and the rear swing-out windows or rear door(s): D Make sure all windows are shut. D Turn the fan on your heating or cooling system to its highest speed with the setting on VENT, HEAT, BLEND or DEF. Additionally, on vehicles with heating/air conditioning systems, NORM A/C or BI-LEVEL A/C can be used. That will force outside air into your vehicle. See "Comfort Controls" in the Index. D If you have air outlets on or under the instrument panel, open them all the way. See "Engine Exhaust" in the Index. Horn Press the horn symbol in the middle of the steering wheel to sound the horn. Tilt Wheel (Option) A tilt steering wheel allows you to adjust the steering wheel before you drive. You can also raise it to the highest level to give your legs more room when you enter and exit the vehicle. To tilt the wheel, hold the steering wheel and pull the lever. Move the steering wheel to a comfortable level, then release the lever to lock the wheel in place. 2-33