Fitting spot lights to a Land Rover

How to fit spot/driving lights

I have written this post because I have seen a lot of postings with people struggling to install spot lamps on their landies.  I think it’s mainly because its electronics and not mechanical.  However, this is easier than you may think.  I have added some diagrams to show you how to do it.

What you will need is to work out how many lights you are going to have and what AMP’s they will take out of the cars electrical system.  This is very important, a lot of land rover owners put somewhere between 2 – 8 lights on the car.

Discovery 1 fitted with 2x55 watt driving lights

Assuming for example you have a set of spots and a light bar or 8 lams and they are using 55 watt bulbs this means you will be drawing just over 36 amp out of your cars electronics system.  This is a heck of a lot and you will need a relay and wired to support this current.  Old Dosco 1's and Defenders only had a 60amp alternator so they do struggle if you have a lot of lights on your car.

I would suggest you do not go mad with the lighting and keep it realistic, I have 2x55 spots on my car and this is enough on the road.  Off road you may need more to cover a wider and of view, or consider CREE LED light bars which use less current.

One last thing is your battery, drawing 36amps with normal lights and also ancillaries would not be good if the lights are on for any extended period of time, therefore a second battery and split charge system may be preferable.

Anyway, you will need for this job;

      Spot lamps
      Wire for the lamps 20 amp
      Crimps including one for piggybacking off the main beam called a tap connector
      Soldering iron, if your going to ensure things don't come loose in the future
      Shrink tubing, to cover your joins and connectors
      Relay rated above your driving lights maximum amp’s


You can get all the above from a motor factors or halfords etc…

The mechanical bit I’ll assume you are OK with, that’s the fitting of the lamps to a bar, or to the car.  On the inside of each lamp there will be a bulb, this will connect to the

Now I have put a wiring diagram below which show an optional switch to allow you to have your light either to come on with the main beam or, be turned on and off from a dash switch.

Example wiring diagram using a relay to control lights

The way the circuit works is when you turn on your high beam, the relay is feed from the high beam circuit to the relay which will then turn the relay on and feed current to your spot lights.

There are a couple of options on the above drawing, firstly a switch co you can control the extra lights you have fitted, if you do not need the switch you can run from pin 85 to earth, or back to the - on your battery.

Another thing you could do is feed the lights from and axillary battery, this is to ensure you do not flatten your main battery on the car. 

On a Discovery 1 300 TDI, you can run a feed wire to pin 86 from an existing wire at the back of the existing lights which feeds the high beam, see below.

High beam feed to relay

The blue device above is called a Tap Connector and you crimp it onto your existing wire and to the new feed to the relay.  This provides the current to the relay.

Your relay will probably look like this.

4 pin 30amp relay for driving lights

You will then need to run the feed wire to the relay and wire the relay in as per the wiring diagram.  when putting connectors together I always crip and solder the connectors and run some shrink tubing over the terminal so tht weather does not get into any joints.  This can end up looking like this.

Connectors with shrink tubing on them

If your going to do what's been done above, label the wires, this way you will not forget where they go.

Anyway, all you need to do is complete the wiring and connect everything up and you should be OK.