Friday, 14 July 2017

Ben's Corner #6: Hidden side of AHO

One of the greatest amendments of this year with respect to two wheelers is the implementation of 'Automatic Headlight On'  (AHO) feature which came into effect this April. Brought along with the BS-IV emission norms, this rule has kickstarted a new era in the history of Indian automobile industry. Now, every bike / scooter sold in India no longer has an independent switch to turn on / off the headlight. As per the rule, the moment key is turned on, the headlight and the rear danger light should glow irrespective of whether it is day or night.

Image Source: Internet

According to the government, this new rule has been implemented to improve the safety of riders on two wheelers. For a layman, it may neither be a deal breaking initiative by the government nor a difficult one to implement but there is more to it than what meets the eye. I will walk you through the hidden side of AHO.


As far as India is concerned, AHO is not new or an out-of-the-box initiative. Right from the early days, there were bikes on our roads with 'Automatic Headlight On' feature including some of the export models of Rajdoot RD 350 but the first affordable officially launched bike in India to sport the feature is the Kawasaki Ninja 250R which was launched way back in 2009. This high performance quarter litre twin cylinder bike had a headlight which remained 'On' irrespective of whether it's day or night. In those days, if there is any bike with a double barrel headlight glowing in the day time, it's none other than the Ninja 250R. The AHO feature gave an unique identity and a gorgeous look to the Ninja which was at that time one of the costliest bikes in the country.

AHO really needed?

From the safety point of view, as against what most people might think, AHO is highly needed for safety of the riders as well as the people on the road even if it's in broad daylight. Doctors say human eyes are highly sensitive to light and can detect them even when the body is exhausted or on the verge of losing consciousness. So, if a pedestrian, while crossing the road, gets fainted, he might avoid an accident if the headlight of the oncoming vehicle remains 'On' during day time.

Secondly, when headlights of two different vehicles are at a close proximity, they might interfere with each other which human eyes easily detect. Experts also say, light helps the brain judge the distance of the oncoming vehicles better. With so much advantages in improving safety, AHO also enhances the aesthetic appeal and road presence of the vehicle. Heck, 'Daytime Running Lights' (DRLs) is a premium feature in cars nowadays.

What it is for manufacturers?

As usual, AHO was not well received by the manufacturers who found ways to implement the feature without touching the overall configuration. If the rule was optional, no one would have implemented as that was how the post implementation turned out. Most of the manufacturers linked the power circuit to the headlight toggle switch which also has the option of supplying power to the pilot lights alone. So, just glowing one or two tiny pilot lights is almost equivalent to non-fulfillment of the rule. That's not all, TVS Motors went one step higher and proved that it's the most intellectual company in the world. Lol! The brand just added a tiny LED light strip below the headlights of its offerings and called it their version of AHO feature. They just couldn't figure out that the letter 'H' in AHO stands for headlight and not any fancy or auxiliary light.

Why manufacturers hesitate?

Image Source: Internet
AHO is not as easy as removing a mere switch. It is directly linked to the engine and its characteristics. Most of the two wheelers sold in India have a simple mechanism to glow the headlight. A dynamo, connected to the engine, produces AC current and glows the headlight when the engine runs. But as headlights mostly require high amount of electricity (35W+10W), they load the dynamo in accordance with Lenz's law reducing its overall power. That's not all, headlights even grab electricity directed towards the spark plugs leading to starting troubles. That's the prime reason manufacturers advise to start the vehicles with headlights off. Some of the notable examples include the starting trouble witnessed by many Royal Enfield owners.

Manufacturers also posted a power drop up to 1 Hp in their offerings as tests will be carried out with headlights 'On'. Honda Hornet's power dropped from 15.67 Hp to 15.04 Hp after AHO implementation. In addition, there are also reliability problems associated with AHO, the headlight circuit which houses limiter, capacitors, bulb, etc., are likely to get worn out sooner than usual. There are also chances of a fire as the wires are forced to carry enormous amount of current whenever the vehicle is operated. So, manufacturers have the necessity to sort out all these issues.

What is the next step?

While AHO is a brilliant feature, it truly has some issues associated with the conventional AC lighting system of our vehicles. But there is a simple solution to avoid this problem in the form of DC lighting system. In a DC lighting system, the current generated by the dynamo only charges the battery while the battery supplies power to the headlight. In this setup, the dynamo is not outrightly loaded enabling the engine to run freely. But, as it requires a stronger battery with a little complicated wiring, manufacturers are reserving this feature for their premium models alone.


In the end, AHO is much needed feature and we should be happy that it has been mandated in our country. Now, it is our turn to press manufacturers to introduce DC lighting system in the offerings even though it may be a costly affair. Hoping for the day when all the two wheelers in India have DC lighting system with AHO.

- S Ben Raja,
Chennai, July 14, 2017.

The above review/analysis is completely the perception of S Ben Raja alone. This does not reflect the views of two or more people or a community. Queries and criticism shall be addressed to the writer only. This author is correspondent for an English daily working on auto beat stories for over a year. Reach him at

No comments:

Post a Comment