1994 GMC Suburban Owner's Manual - Page 202

Making Turns When you're turning with a trailer, make wider turns than normal. Do this so your trailer won't strike soft shoulders, curbs, road signs, trees, or other objects. Avoid jerky or sudden maneuvers. Signal well in advance. Turn Signals When Towing Trailer a When you tow a trailer, your vehicle has to have a different turn signal flasher and extra wiring. The green arrows on your instrument panel will flash whenever you signal a turn or lane change. Properly hooked up, the trailer lights will also flash, telling other drivers you're about to turn, change lanes or stop. When towing a trailer, the green arrows on your instrument panel will flash for turnseven if the bulbs on the trailer are burned out. Thus, you may think drivers behind you are seeing your signal when they are not. It's important to check occasionally to be sure the trailer bulbs are still working. Driving On Grades Reduce speed and shift to a lower gear before you start down a long or steep downgrade. If you don't shift down, you might have to use your brakes so much that they would get hot and no longer work well. On a long uphill grade, shift down and reduce your speed to around 45 mph (70 km/h) to reduce the possibility of engine and transmission overheating. When towing at high altitude with steep uphill grades, you need to consider the following information. The lower atmospheric pressure at high altitude allows your vehicles engine coolant to boil at a lower temperature than at normal altitudes. If you immediately turn your engine off after towing at high altitude with steep uphill grades, your vehicle may show signs similar to engine overheating. To avoid this, let your vehicle operate in a parked position with the transmission in "N" (Neutral) for a few minutes before you turn off the engine. If you do get the overheat warning, see "Engine Overheating" in the Index. If you have an automatic transmission, you should use "D" (or, as you need to, a lowergear) when towing a trailer. Operating your vehicle in "D" when towing a trailer will minimize heat buildup and extend the life of your transmission. If you have a manual transmission and you are towing a trailer, it's better not to use fifth gear. Just drive in fourth gear(or, as you need toya lower gear). 4-42