How I installed DRLs

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FlyingPete

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Coventry
Like them or loathe them, most cars from 2011 onwards will have some form of daytime running lights (DRLs). Often (and in many cases, justifiably) derided as a chavvy styling feature, some of the LED types are excessively bright, or incorrectly wired in the case of aftermarket retrofits. However, a sensible set of DRLs can serve as a useful substitute to using your headlights during the day. While in the UK it's currently not compulsory to drive with headlights on, it's possible that we may soon follow suit with other countries, which require the use of headlights or DRLs during the day in winter months.

For my 90, I've been trying to keep things close to standard where possible, or at least period-correct. So I didn't want to add aftermarket LED strips to the front of my Landy. There is however an alternative which was originally done by Volvo on their 240. Dual-filament bulbs in the front marker lights can double up as DRLs as well as parking lights, with no cosmetic changes to the vehicle. This is what I decided to do.
DSC00876.jpg



You will need:
A Land Rover 90/110/series2/series3.
A 5-pin relay
Possibly an extra 4-pin relay (see below)
Two defender tail/brake light housings with bulbs
General wiring bits​


Since DRLs are necessarily bright enough for daytime use, they are too bright for use in the dark and may dazzle other drivers. So when the headlights are switched on, DRLs should go off or dim down to front marker light intensity.

DRLs ideally need a power supply which is active with the engine running. You could use a key-switched supply, but my 90 doesn't have an 'accessory' position on the switch, and I didn't want to have DRLs on when I'm just parked listening to the radio. Twin towbar electrics (12N+12S) have a connection which is live with the engine running, so I used that to switch my DRLs. Otherwise you will need to install a new circuit, using the alternator warning light connection to trigger a relay.

How it works:

When you start the engine (or alternatively turn the key to the 'run' position) the power supply to the brighter 21w filaments in the bulbs will be energised, lighting up your DRLs. When you turn the lights on (energising the 5w filaments in the same bulbs as marker lights) the power to the DRLs will be interrupted by a relay. When the engine is off, the 5w filaments can be used as parking lights in the usual way.
DRL wiring.png

Connecting it up:

The first job is to arrange the power supply for the lights. I made use of the relay in the towbar wiring for this. This is triggered by the brown/yellow wire that operates the charge warning light- which rises to 12V once the alternator starts generating power. From this relay I connected two fused circuits- the existing one at 15A for the towbar socket, plus a new one fused at 5A for my DRLs. You'll need to run a wire through the bulkhead and into the engine bay. This will provide power to the DRLs when the engine is running.

On the other side of the bulkhead, we need to interrupt the power supply to the DRLs when the standard lights are switched on. The simplest way to do this is to connect the DRLs to the 'normally closed' terminal (87a) of a 5-pin relay. The relay takes a trigger from the parking light circuit, so breaking the connection to the DRLs when the lights are switched on. I installed this relay in the engine bay, but you could install it in the main fuse box instead if there is space. Either way, run new connections from the relay to the light clusters in the front corners of the Landy.


Now we can fit the new lights. Since the lights on a Land Rover are all the same size, it's a simple matter of removing the old front lights, and replacing them with the combined tail/brake light assemblies. The dimmer filament (normally the tail light) connects to the existing parking light circuit and functions in the same way. The brighter 'brake light' filament connects to the new feeds for the DRLs. Refit the clear lenses you took from the old lights, and you're done!


Now, when you start the engine, the bright DRLs should come on, for extra conspicuity during the day. Switch on the lights, and they will dim down to the parking light intensity. Best of all, no changes to the exterior appearance of your Land Rover.

DRL.png

The difference in intensity between the two filaments- DRL on the left, parking light on the right.

Other ideas:

An additional function can be obtained 'for free' from this circuit. As it stands, pin 87 on the relay is unused. This can provide a circuit which is live only when the engine is running and the lights are on. One possible use for this is extra front position lights- for example if you've installed extra high-beam headlights which have an inbuilt marker light. You wouldn't necessarily want these to be lit if you're just parked on the road at night. But by connecting them to the unused terminal on the DRL relay, they will be lit when driving at night, but not while parked. The DRL circuit should be fused at 5A, which is enough for four pairs of extra marker lights.
 
Interesting and well written but what exactly is the problem with just switching on your sidelights?

Recently I've started to think that DRLs are almost dangerous, so many people are just thick as **** and use DRL's instead of turning on headlights leaving the rear unlit at night. The other day I saw a matt black BM with smoked rear lights, tinted windows, with no lights bar the front DRL's, was almost invisible from the back.
 
Sidelights are pointless during the day. They are only intended for parking at nights on unlit roads. Dim-dip was briefly introduced to try and compensate for people driving at night with just parking lights. Similarly, full headlights are overkill during the day and make motorcyclists less conspicuous. But there is a proven benefit to having dedicated DRLs- not to see by, but to be seen by other road users. How much do you actually see when you glance in your rear-view mirror, for example.
DRL-light_comparison.jpg


Headlight-based DRLs are what's dangerous IMO, especially since the dashboard often lights up too. They are a cop-out by manufacturers that gives no immediate indication as to whether the headlights are actually on when needed. I've passed several cars that were completely unlit at night, since the driver could see where he was going and presumably thought the headlights were on. Whatever system you use, there will be incompetent drivers who don't know how to use them correctly.
 
and England is the only country that has such bright drl.
some thing the government look in to and passed
 
I suppose since I have LED side lights they are a hell of a lot better than the standard bulbs. Though with alot of new cars the DRLs are no brighter than the sidelights in the first place.
They would give as similar effect to DRLs, though if they're bright enough to be seen in the day, they might cause issues with glare at night. The dipped beams have a shaped pattern specifically intended to avoid dazzling oncoming drivers. Mine are configured so that with headlights on, the DRLs revert back to parking lamp brightness. More to the point, I had all the necessary parts lying around not doing anything, so it cost me nothing to install :)
 
Haha fair enough!

The new cars should all have auto lights now, how expensive could it be to add an extra sensor! Would stop the bellends from using DRLs as headights.
 
Interesting and well written but what exactly is the problem with just switching on your sidelights?

Recently I've started to think that DRLs are almost dangerous, so many people are just thick as **** and use DRL's instead of turning on headlights leaving the rear unlit at night. The other day I saw a matt black BM with smoked rear lights, tinted windows, with no lights bar the front DRL's, was almost invisible from the back.

Totally agree with this, have seen numerous plonkers driving around with DRL's only and no rears lit.
 
and England is the only country that has such bright drl.
some thing the government look in to and passed

The regulations governing vehicle lights are the UNECE regulations.

The UK government has not passed any laws on the brightness of DRL's.

So the maximum legal brightness of DRL's is the same throughout Europe.

Converting an existing side/parking light to act as a DRL is illegal as it invalidates the original E mark type approval.


Brendan
 
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