I had purchased a
RE Hunter 350 in September last year. Bit by bit, the bike was accessorized according to my liking. The bike is used primarily for office commute and short rides and ownership experience so far has been relaxed compared to my earlier vehicle, a decade old CBR250. While CBR is a good vehicle, maintaining such vehicle in a rural area has its own challenges. The CBR ownership and challenges it threw, will need another thread and shall not drag it here.
In this post, I’ll focus on how the AHO (automatic headlight ON) was disabled in my bike using a simple mod. This mod is universal and can be applied on most vehicles. On the advent of BS4 vehicles, Govt. had mandated DRL (daytime running lamp) for two wheelers. Companies like TVS provided a dedicated LED DRL in most of their vehicles, whereas most manufacturers chose to keep the low beam always on and removing the headlight on/off button altogether. The contribution of such measures to improving road safety is debatable.
![DIY: Disabling the Automatic Headlamp ON (AHO) in a Hunter 350-xl.jpg](https://www.team-bhp.com/forum/attachments/motorbikes/2581936d1710159486t-diy-disabling-automatic-headlamp-aho-hunter-350-xl.jpg)
There are different methods available to disable the always on headlight such as adding an extra switch to low beam wire / change the handlebar OEM switch assembly to one of an older model / get a plug-in module to wiring harness. I didn’t want an extra switch poking out of handle bar and the second option (OEM switch assembly) was also not possible as Hunter never had an older with headlight on/off button. The aftermarket plug-in module also seemed expensive for the function it offered.
Being a DIY enthusiast, it was time to apply some of it to this problem (self-thought one). One solution was to form a two-relay based setup which shall switch off the low as the vehicle is started. I had bought these relays and made a wiring diagram, but to mount the relays space was a constraint. It had to be placed under the seat and the wiring had to be routed under the fuel tank to headlight area. I kept the plan under hold and was on the lookout for further options.
A wildcard entry to my plan was a photo-relay (Photosensitive relay). It was already used in our household to automate external lighting after dark. These relays however were rated for 230-volt AC and 12-volt DC options were exorbitantly priced.
Few hours of google search and I ordered a 12-volt DC photo relay from a Pune based components supplier online. It reached me in a week and work started.
Let the pictures do the talking.
Headlight cover removed.
It had enough space to route wires and had hold a headlight coupler (male to female). The H4 coupler makes the whole process free of any wire cutting / disturbing the factory wiring.
The photo-relay and wiring harness.
![DIY: Disabling the Automatic Headlamp ON (AHO) in a Hunter 350-20240218_155611.jpg](https://www.team-bhp.com/forum/attachments/motorbikes/2581938d1710159486t-diy-disabling-automatic-headlamp-aho-hunter-350-20240218_155611.jpg)
The relay mounted under headlight and behind number plate, neatly concealed.
Waterproof connector from headlight coupler to relay.
Whole setup is removable in 15 mins to stock form.
Outcome:
The relay gets power as the bike turns ON (engine starts) and light (low beam) stays OFF during day. As daylight intensity falls, the relay output switches and gives power to Low beam wire and headlight becomes ON. The daylight intensity switches the relay typically around evening around 6pm in our area and is ideal. The placement of relay behind the number plate ensures that the headlight doesn’t turn off at nighttime while light beam of an opposite vehicle might fall on it.
Even during day, one can turn on the headlamp by placing the switch on HIGH beam as only low beam wiring was modified.
Pros:
Low beam off during day / reduced electrical load / DIY = satisfaction!
Cons:
At a dim lit area, when the low beam is kept ON by photo-relay, if high beam is turned ON, it will cut supply to the relay (but high-beam will be working normally). When beam is changed back from high to low, the relay needs 2-3 seconds to power ON and switch ON the low beam. This will cause a condition of no light for 2 seconds while changing from high to low. This condition is OK for me according to by bike usage pattern (minimal night usage / well illuminated roads) but may not suit everyone else. One can however use the PASS switch normally without any such effect.
Verdict:
A simple but effective DIY for me. Personalizing one’s bike is a joy indeed. All the components required can be sourced online and can be completed in less than an hour. The bike has an additional pilot lamp ( T 10 , 5 Watt bulb) inside headlamp housing which is always ON for people who are worried about no headlight during day.
Cheers!!! ![Thumbs Up](https://www.team-bhp.com/forum/images/smilies/thumbs up.png)