Q: Voltage drop noticed during night driving. The headlights dim and then return to normal.
While driving at night notice headlight dim low and brighten up. Voltage shows drop for a second. Bad ground?
My car has 105000 miles.
My car has an automatic transmission.
Recommended Services
| Electric Problems Inspection | $94.99 - $114.99 | Get a Quote |
This may be a sign of a failing voltage regulator or potentially a bad ground connection. As you may know, the voltage regulator regulates the charging of the battery by the alternator. When the voltage regulator is not working properly, this will result in the alternator allowing too much power to be delivered to the battery, damaging the wires and prematurely destroying the battery.
In other cases, it may result in the alternator not supplying enough power to the battery, causing the battery to be undercharged or not charged at all. In either case, I would recommend having an expert, such as one from YourMechanic, come to your location to diagnose your vehicle’s charging system and suggest the needed repairs.
The statements expressed above are only for informational purposes and should be independently verified. Please see our
terms of service
for more details
Get an instant quote for your car
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing
What others are asking
Loose steering causing engine to stop
Hello. If you are referring to the steering lock pin that locks the steering wheel in place when the key is turned off, then this can cause the engine to stall as it can also affect the ignition switch. If...
After sensor replacement, 2nd diagnostic revealed P0139
No, it is not the catalyst. The P0139 code (https://www.yourmechanic.com/article/p0139-obd-ii-trouble-code-o2-sensor-circuit-slow-response-bank-1-sensor-2) is for the O2 sensor before the catalyst. The code is illuminated when the engine control module is testing the O2 sensor and it cuts the fuel to see if...
Why is my minivan difficult to start when the engine is warm, but not when it is cold?
Hey there. There are a couple of reasons why this could be happening. I have seen a faulty coolant temperature sensor (https://www.yourmechanic.com/services/coolant-temperature-switch-sensor-replacement) cause this problem on warm start up. There also could be a problem with the crankshaft position sensor...
Crank no start - 2002 Hyundai Santa Fe
Hey there. I would expect that you have a Check Engine light on, and there are problem codes set (https://www.yourmechanic.com/article/how-to-read-and-understand-check-engine-light-codes-by-jason-unrau) which would be helpful. Leave the coil wiring connected, remove a spark plug, keep the metal casing grounded, and turn...
Will a v 6 chevy fuel injector fit in a 2.2 4 cylinder
The fuel injectors in a V6 versus a 4 cylinder motor will look the same and may even fit, but the orifice size of the tips may be different. Injectors have different size flow rates of how much fuel they...
Noise and vibration when driving that stops when I hit the breaks
This may be a sign of failing or worn out wheel bearings. A wheel bearing (https://www.yourmechanic.com/services1/wheel-bearings-replacement) will usually fail due to pitting or small damage on the surface of the rollers or the bearing race. Both the surface of the...
When engine is on in either reverse or drive the car bounces slightly but not in neutral or park and not all the time.
Hi there. When the front end becomes bumpy while driving, it's typically caused by struts that are worn out, steering stabilizer bushings that are damaged or a different suspension component that is beginning to wear. In order to correctly diagnose...
So I found out mt husband used castrol high mileage 5-w30 oil on my gmc terrain sle 2013 and im panicking. Is that oil okay?
The high mileage oil brand, and the specific viscosity rating (5W-30), that your husband bought for you is perfectly acceptable and you needn't worry at all. High mileage oil simply claims to have "extra" engine oil seal conditioners and perhaps...
My 07 explorer 4.0L hesitates and hums when I'm on the gas pedal, but I can accelerate smoothly and quietly using cruise control.
The noise and loss of power may or may not be related. The vibration might be related to the poor operation but other causes such as faults in motor mounts can cause vibration not to mention a faulty harmonic balancer....
Related articles
Can a Bad Sensor Prevent a Car From Starting?
If your car isn't starting or has a hard time starting, a faulty sensor may be to blame. Car sensors monitor data to keep your car running smoothly.
The Best Used Cars to Buy If You Just Retired
Here’s Here’s a cruel, hard fact – car manufacturers no longer target seniors. Instead, they devote their time and energy to appealing to the 18-45 demographic. Still, some features make certain cars more suitable for older drivers. We have evaluated...
How to Clean and Restore Headlights
Even Even owners who regularly clean and maintain their vehicles are not immune to wear on their headlights. As the vast majority of headlights are made of plastic, they require different care than other exterior surfaces of your car. Plastic...
Browse other content
Cities
Estimates
Services