How to Recognize Signs That a Yukon Alternator Is Going Badby Josh Baum
The alternator in your Yukon Denali is a critical component; if it fails, you won't be able to drive very far or very long before the engine shuts down. The alternator converts the mechanical energy generated by the engine's moving parts into electrical energy, which is used to continuously charge the battery. Alternators often burn out slowly, producing various warning signs that the end is near. If you recognize and heed these warnings, you can replace the alternator before it fails completely and strands you somewhere.
Start the Yukon and pay close attention to the sound of the engine as it turns over. If the engine struggles more than usual or takes a long time to start, it's a sign that the alternator could be going bad. If the engine doesn't turn over at all, that's a sign that the battery is completely dead, which can be caused by a failed or nearly failed alternator.
Watch the battery meter on the instrument panel as you leave the car running and take it on short trips. The battery meter is located at different locations on the dashboard on various model years of the Yukon, but you can identify it by the battery-shaped symbol printed in the center. The needle on the meter should stay right in the center. If you notice the needle dropping as you drive or leave the car idling, that's another fairly reliable sign that the alternator is going bad.
Run the heater. Hold your hands in front of the vents and try to determine if the air temperature is colder than usual or if the air pressure is weaker than usual. These are usually among the earliest and most noticeable symptoms of a failing alternator.
Observe the brightness of all lights and electronic displays inside and outside of the vehicle. As the alternator weakens and begins to fail, it feeds less and less voltage to the Yukon's lights. In most cases, the lights will dim before they go out entirely. If you observe noticeable dimming of various lights, particularly if multiple lights seem to dim in a synchronized pattern, it's usually a symptom of alternator failure.
Take note of any electronic components that turn off unexpectedly. Typical examples would be if the radio or navigation system suddenly loses all power. This is not only usually a sign of alternator failure, it is also a sign that the alternator is just about to completely fail.
- "Auto Repair for Dummies"; Deanna Sclar; 2008
- "Chilton GM Full-Size Trucks, 1999-05 Repair Manual"; Chilton; 2006
- All of these symptoms can technically be caused by other problems like a failing battery, loose belt or bad wiring. Taken together, however, they indicate a pretty clear likelihood of a failing alternator.