46 votes
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Car won't start, horn won't honk, headlights won't come on, what could cause this?

The symptoms all point to a faulty battery, and an incorrect test result for the Autozone battery test. Starting with this: Hitting brakes: Brake lights come on and interior lights dim: a good ...
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  • 4,412
34 votes
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Do matching (left/right) lights often burn out within a short time period of each other? If so, why?

No, the salesman was spot on. If you think about it, bulbs are designed to last about the same amount of time. If they are installed in pairs, then the secondary light which matches the first will ...
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16 votes
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Realistically, how much can I expect to improve cloudy headlights by polishing?

That process you're describing is VERY familiar to me - I do that for people from time to time. The difference is REALLY SIGNIFICANT... and at most it should take you five minutes of actual work per ...
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  • 2,534
16 votes
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Why do LED running lights turn off while the turn signal is blinking?

The main purpose for this is so other drivers can see your turn signal. The LED lights are so intense, they do not allow the oncoming driver to be able to see the turn signal. By turning the LEDs off, ...
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15 votes

How to upgrade a motorcycle battery to a bigger AH battery?

Sure you could put a bigger battery in .What may happen is that the total proposed draw is too much for the dynamo and it will go flat.Even if it does not go flat because your appliance usage patterns ...
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  • 2,051
15 votes

Car won't start, horn won't honk, headlights won't come on, what could cause this?

All symptoms point to a dead battery, but as you have already attempted to rule that out, the next thing I'd check would be bad connections or cables. Turn on the headlights or something else that ...
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13 votes
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Why are H4 LED headlights not designed correctly?

I think you hit it. Cost, most of the LED headlights are made to just pack as many LED as possible into the H4 package as possible, but a small percentage of them are actually designed to mimic the H4 ...
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11 votes

Motorcycle Headlight Conversion

absolutely DO NOT replace a BALLAST with a RELAY. They perform different functions completely and are in no way related. Relay = Switch Ballast = Current Regulation A solid state relay may have some ...
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10 votes
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What is this extra light on my headlights?

According to this that extra space is for the integrated fog light, which is probably where the fog light would be if you didn't have the separate fog light.
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  • 1,502
7 votes
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Is it a cause for concern if one headlight beam points lower than the other

I would say the two peaks should be at the same height. In the UK, beam alignment is part of the annual MOT roadworthyness test, and the government publish a guide as to how to set them up: https://...
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7 votes

Weird headlight issue!

Each bulb usually has 2 filaments in it, one for low beam and one for high beam. One possibility is that your driver's side bulb has a broken high beam filament and the passenger side has a broken ...
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  • 20.8k
7 votes

Do matching (left/right) lights often burn out within a short time period of each other? If so, why?

Lightbulb failure is a random event, which is not pre-set to happen after X hours of service or before a certain date. It is provoked by stress from vibration, repeated heating up and cooling down and ...
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6 votes

Putting three headlights on my bike

Do you have a Pulsar 220? If so, you probably don't want two full-blown headlights, if the electrical system on a 220 is anything like that of the 135LS. On my bike, the electricals can barely keep ...
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6 votes

Low beams out high beams work

I would bet the problem lies in the relay, which should be located under the hood. It should look something like this: Each of the high beams and low beams will have their own relay. The switch which ...
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6 votes

Collision repair with Bondo and used parts

I recommend looking for a replacement side panel. Otherwise the standard panel beating approach is to try and hammer out the worst of the dents first. Car bog/filler/bondo is a last step to fill minor ...
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6 votes

Daughter's 2005 Nissan Sentra 1.8 SE - No Low Beams - High Beams Fine

It really looks like it's down to the switch, if the high beams work normally (Not just using flash to pass) and both low beams quit at the same time, and you are positive the bulbs are good. The one ...
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6 votes

Can I Mount auxiliary lights for Hero Honda Passion 2002 bike?

I would not want to increase load to your dynamo. I'm skeptical that you actually have that type of charging system but can't back my claim. IF it is a dynamo then I would do something in order to ...
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6 votes

Single headlight does not come on but is not burnt out

Sounds like the bulb socket is corroded. You could try spraying it with contact cleaner, or trim an emery board to fit and giving a couple of passes with that to remove the corrosion. With any ...
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  • 2,301
6 votes
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low beam does not work, daytime running and high beam do

Most vehicles not using an LED headlight have multiple filaments in the bulb. These frequently do burn out independently. Low beam is also the most used filament, and likely to burn out first. Given ...
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  • 583
6 votes

Are expensive high-brightness 55W headlight bulbs worth the investment?

I think there might be a regulatory component that effects stated brightness I found in CFR (Code of Federal Regulations) 49 The maximum wattage at 12.8 volts (design voltage): 65 watts on upper ...
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6 votes
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Head light bulbs

If the bulb in question is the same fitment as the original (is just a higher wattage or whatever), then it should cause no issues with the wiring. I believe the main differences can be linked back to ...
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5 votes
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Right side highbeam not working on on Mk2 Golf GTI - not fuse or bulb

Bulbs - Swap the bulbs, like the comment suggested, with the ones on the other side. If works switch back and get replacement. Fuse - Swap the fuse with another in the fuse box with the same rating. ...
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  • 66
5 votes
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Are there any (legal) ways to increase halogen headlight brightness?

It is possible that the adjustment is not correct, i.e. the lights are still shining too steep down though the knob is set to 0. Though you can test this on your own, shops will do this with more ...
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  • 7,007
5 votes
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How to upgrade a motorcycle battery to a bigger AH battery?

As Autistic and Chenmunka say, if you want to increase the electrical power you're using (by having a higher-rated headlamp), you'll need to generate more power - by having a bigger alternator or ...
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  • 28.6k
5 votes

Sealing / effectively preserving restored headlights

The best way to keep them looking good is to utilize clear spray lacquer which is is not affected by UV. UV light is what causes the cloudiness in the first place. By spraying the clearcoat on there, ...
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5 votes
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How to fix 2007 Mercedes SLK daytime running lights?

After hours of tracing cables, removing panels and taking apart more of the car than I'd like to admit, I figured the issue out. Apparently there's a cable for control current (or something like that)....
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  • 251
5 votes

How important is bulb grease when changing low-beam or high-beam headlights?

No, you don't "really need" it. However, the purpose of the grease is to keep out moisture that can degrade the connection and the bulb's performance. So if you see any signs of corrosion when you ...
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  • 14.3k
5 votes
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How important is bulb grease when changing low-beam or high-beam headlights?

It depends. What you are referring to is dielectric grease. It doesn't conduct electricity so it is safe to use on electrical connectors. Modern vehicle assembly lines don't grease bulbs because the ...
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  • 1,551
5 votes
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Why do the headlights of supercars looking flashing on video

They flash because that's how their brightness is altered. Rather than use a large resistor to vary the current through the LEDs, they are flashed on and off faster than your eye can detect. When they ...
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  • 9,286

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