So I am having a problem with the daytime running lights on my 2004 Chevy Silverado pickup truck. The issue is that the voltage that runs to the daytime running lights spikes between 12v - 14.5v and causes the light bulbs to burn out. I have already replaced the bulbs multiple times and am getting tired of this patchwork solution.
So is there a way I could attach a voltage regulator in-line to the lights so that it will not spike? If so, what kind of regulator would I get and what kind of specs am I looking for? Any ideas where to buy this kind of thing?
I’ll let the real car guys answer the question, but IIRC 12-14.5v is the normal operating range for the DC system in most cars. Also, how do you know/why do you think it’s spiking? I assume you’ve measured it. What is it normally at that you are considering 12v a spike. I get the feeling it’s actually running a low voltage and perhaps the system has a partial short to ground somewhere (and when the truck is running the vibration makes the hot and ground stop touching, sending all 12v to the socket and you are registering that as a spike).
The GM trucks (and cadillac) vehicles have known problem where the day time running lights have power spikes. They “remedied” the problem by replacing the standard 3156 bulbs with 4114 bulbs (that can “handle” the spikes. I am replacing the bulbs with LEDs that cannot handle the power spikes. I need to find a solution to regulate the power at a steady 12v or less. Thanks!
Sure, you can put a regulator on your LEDs - get an LM7812 regulator. Remember that you may need to get rid of a lot of heat, depending on the current rating of the LED lamps, so the regulator is going to need a heatsink. The amount of heat is (Vin(Max) - 12v) * Ilamp. In Watts.
Take into consideration that the led bulb may only have the leds on the front of the bulb. A lamp that uses a 3156 is normally designed to reflect light from the rear of the bulb, as the original is designed basically as a globe. I’ve seen more than one customer purchase leds only to find out the light they put out isn’t up to par with the originals. But if you’re only using them for looks it might not be an issue.
Over the years I have had motorcycles which had the same problem of burning out lightbulbs and I just inserted a resistor in series which would limit the current. I am talking about lights like running lights or brakes where you do not really need the full output. A simple resistor will prolong the life of the lights forever.
By the way, I have recently been messing with the lights of a Silverado because I could not get the fog lights to work. I finally gave up as it was not that important.
12 volts in a car isn’t 12 volts. It’s usually about 12.6 volts when the car is off, and will typically be a volt or two higher than that while the car is running. Somewhere around 14 or 15 volts is perfectly normal and is a good quick and dirty indication that your alternator is working.
Automobile bulbs are designed for these voltages. Either there’s a design flaw in these bulbs or there’s something else going on here.
It is possible that you are getting some rather severe voltage spikes that are short enough in duration that a multimeter will filter them off. This could indicate a problem with the voltage regulator in your alternator. You aren’t going to see this type of problem with a multimeter. If you have access to an oscilloscope you can see how “clean” your voltage is. I see nothing in your post that indicates that this is what is going on though, so don’t go replacing your alternator just because you think you’ve got a voltage spike problem. Like I said, 14.5 volts is within the normal operating range of most cars and by itself does not indicate a spike.
Also, make sure you don’t touch the bulbs with your skin while you are installing them.
As has been mentioned by several other posters a 12V automotive electrical system is not really 12Volts. A fully charged battery is about 12.6 V and due to resistance in the battery the alternator puts out between 14-15.5 volts.
If you need 12 or less, you will need a regulator of some sort.
If the OP is purchasing an aftermarket component intended for use on cars, it should work correctly & not suffer damage when exposed to 14+ volts indefinitely. If it is failing, the problem is more likely to be crap Chinese parts than the car itself. So get a new component from a different manufacturer.
If the component is not intended for cars and really does have a 12.0 volt limit, then he/she will need a regulator to convert car 14+ volts to component 12.0 or less volts. Or better yet, buy a component intended for use on cars.
Bottom line: The problem is not in the car, it’s the OP’s aftermarket component.
Cite? When Volvo brought them to the US they cited studies that showed about an overall 25% reduction in accidents. They are particularly effective on secondary (non-divided) highways.
Sure, but the accidents they prevent would have themselves been prevented by turning on one’s headlights - something competent drivers do at dawn and dusk, and incompetent ones don’t.
They’re a band-aid for a totally unrelated problem, which is the ridiculously low standard of competence require to obtain a driver’s license in the US.
"If you need 12 or less, you will need a regulator of some sort. "
Ah, but what is this mythical regulator that I need?
All of the LED bulbs that I see out there for sale specifically state “not for use in GM DRLs” for this reason.
Not knowing electrical stuff, I am trying to find out exactly what this regulator I need is.
-Really not all that bright either.
I guess I didn’t make myself clear, they were talking a daytime accidents. And those stats came from Europe, not the USA, so our level of driver’s training is immaterial.
So I repeat, cite?
