Why are the lights flickering on my GMC Sierra?

Why are the lights flickering on my GMC Sierra?

Keep in mind that some minor flickering is normal and is due to the changes in output voltage of the alternator as controlled by the PCM. This vehicle had a swing in voltage of up to .8 (eight tenths) of a volt. That is not normal.

Why are the lights flickering on my 03 Denali?

On my 03 Denali, the headlights and interior lights flicker really bad at any given time. There is no rhyme or reason on when they flicker (like bumpy roads), but I know it drives me and the car in front of me nuts.

Why do the lights flicker on and off in my car?

There is no rhyme or reason on when they flicker (like bumpy roads), but I know it drives me and the car in front of me nuts. Sometimes during these flickers, I can hear the whoosh noise coming from the brake pedal as if the traction control is kicking in and slighty feel some brake being applied even though my right foot is on the gas.

Are there any problems with my 2005 GMC Sierra?

This 2005 GMC Sierra came in with the complaint that when the vehicle is started cold, the headlights, dash lights and dome light will flicker or pulsate. As the system runs the problem diminishes but never goes fully away. This is a common complaint on many Cadillac, Chevrolet and GMC full sized trucks and suv’s.

Keep in mind that some minor flickering is normal and is due to the changes in output voltage of the alternator as controlled by the PCM. This vehicle had a swing in voltage of up to .8 (eight tenths) of a volt. That is not normal.

This 2005 GMC Sierra came in with the complaint that when the vehicle is started cold, the headlights, dash lights and dome light will flicker or pulsate. As the system runs the problem diminishes but never goes fully away. This is a common complaint on many Cadillac, Chevrolet and GMC full sized trucks and suv’s.

Why are my headlights flickering on and off?

The real problem as it turns out was the voltage regulator inside the alternator as the factory ones are weak. This was an easy and inexpensive fix. Taditel and Transpo both make redesigned heavy duty voltage regulators for the factory AD244 130 amp alternator for under $20.

Why does my GMC Sierra have a spark?

This test is a low tech way of checking for a poor ground or power connection condition. It is VERY IMPORTANT that the jumper wire always be connected to the battery first and then to the alternator. If there is a problem there WILL be a spark. The bigger the problem the bigger the spark. A spark near a battery can result in an EXPLOSION.