Fog Light Conversions for beginners

Because of Mike's (Sonicsoop) experiences, and the difficulties others have experienced with this, I decided to put together a quick how to on the Thor Fog Light Conversion. Thanks to Jase_93TT for selling me the lights and looms so I could have another crack at this in order to document it;). If anyone is interested in these lights and looms now that the hard work has been done let me know.

NB: For all those of you that have had problems with this in the past, take heart, this was my second attempt and I found a couple of new gotchas this time round.

Mike

2 rear lights - most of you will already have these

2 rear light looms - and these too

8amp wire (green, black, red, green-and-white)

insulating tape (black, white as a start)

assorted blade connectors

2x 12v 30A spdt relays (maplin N00AW)

4x 15Ω 10W wirewound resistors (maplin H15R)

1x diagram showing how you are going to do it - see below

The first picture shows how and why the most common mistake in this conversion is made. The original Thor diagram suggested that the Green (G), Green-and-white (Gw), and White-and-black (Wb) wires should be cut into, the most common mistake made is through cutting into the wires before they split, this results in the ever popular "4 fogs and no brakes" mod.

The simple solution is to cut into the wires after they have split into two. However the problem here is to identify which wires go to which bulb. In my case the inner brake light wires had already been cut into close to the bulb for a simple fog conversion. I decided to tap into them there and feed the extra wires through the bulkhead grommits.

For the first light you will need to cut the G wire, cut the Gw wire and strip the insulation from the Wb wire (picture 1).

You will need 2 G, 2 Gw (I wrapped mine with white insulating tape) and one wire for the Earth (in my case I used black). These wires need to be long enough to reach the middle of the boot from the light through the bulkhead. Label each end of one G and one Gw so that you can tell them apart - I used some black insulating tape. Feed these 5 wires through the bulkhead grommit to where you will be making the connections.(picture 2)

Solder the non marked wires to the bulb ends of the corresponding coloured wires. Splice the Earth wire to the Stripped Wb (picture 3) and insulate the connections

Solder the marked wires to the loom ends of the corresponding wires where they were cut and insulate these connections(picture 4).

Remember you will need to feed these looms through the bulkhead so don't you be connecting to the relays before the lights are in the car. For this reason I used female blade crimp connectors at the end of each wire, and a ring crimp connector for the Earth. (picture 5)

For the second light there isn't as much to do as on the first.

You will need to cut the Green (G) and the Green-and-White (Gw) wires. Strip back the bulb ends of each, but leave the other end insulated, this end will need no connection (picture 1).

Feed one G wire, and one Gw wire through the bulkhead grommit and solder to the bulb wires of the corresponding colour. insulate the connection and the bare loom ends of the cut wire (picture 2)

Once again these wires will need to be fed through the rear bulkhead, so make your life simple and use blade connectors. In this case I used piggy back connectors on both these wires (picture 3)

In order to make the wiring a little simpler I made a number of smaller wires as in picture 1

1) this is a short length of wire which will be used to feed the switched live from the fog switch, for simplicity I added a male blade connector at the switch end, I spliced 2 female blade crimp connectors (which will connect directly to the relays).

2) same again, this is for the Earth connections from the relays. A ring connector at the Earth end and I spliced 2 female blade crimp connectors for the connections to the relays.

3) because it is going to get quite crowded around the relay this is a short extension

4) this connector will bridge the two relays, one end is a female crimp, the other is a piggy back connector

5) These are the resistors to avoid the bulb fail light. I decided to put crimp connectors on the end in case I needed to replace them at a later date. they are just taped together using insulating tape. (one end is female, the other is male)

6) These are the connectors to fit the resistors to the circuit. One is just a short extension, M-F and the other is F-ring crimp connector

You will need 2 12V 30A SPDT relays (maplin part number N00AW) (picture 1).

Be careful when selecting these from the store as they look remarkably similar to the N01AW shown in picture 2.

Word of advice These won't work! The eagle eyed amongst you will note that the N01AW are 24V

Now pay attention as I'm sure I'm going to lose a couple of you here. The photos here aren't terribly clear, but hopefully will help you to follow the main wiring diagram. I'll be referring to the extra wires from the photo in post 6 by number

pin num (relay num)

1) Connect wire 4 between pins 87a(1) and the piggyback to 87(2) as in picture 2

2) Connect wire 1 between pins 86(1) and 85(2) as in picture 3

3) Connect wire 2 between pins 85(1) and 86(2) as in picture 4

4) Connect resistors 5 between the two wires in picture 6 and connect to pin 87 of relay 1 as in picture 5

Fit the lights to the car, and pass the wires through the bulkheads, reconnect the multiplugs in the boot area.

5) Connect wire 3 to pin 87a of relay 2

Take the second light (with 2 wires):

6a) Connect the G wire to the extension on pin 87a of relay 2

6b) Connect the Gw wire to the piggyback connector on pin 87 of relay 2 as in picture 1

Right this is where it gets really messy

Take the first light (with 5 wires):

7a) Connect the marked Gw wire to pin 30 of relay 1

7b) Connect the marked G wire to pin 30 of relay 2

7c) Connect the unmarked G wire to the piggyback connector on pin 87a of relay 2

7d) Connect the unmarked Gw wire to the piggyback connector on pin 87 of relay 2 as in picture 2

The three earth rings need to be earthed, I found the earth point at the centre of the boot bulkhead works well.

Now it's time to test the lights, and also time for Gotcha number 2. Might I suggest at this point that you check the bulbs that are fitted to each of the brake lights.

If your bulbs haven't blown then you should get the following:

picture 1 - tail lights

picture 2 - fog lights only

picture 3 - fog lights and brakes

picture 4 - no fogs and brakes

I thank you.

Mike

moderate this!

i hate annoying drunk peopole!

okay if you insist - your spelling is like a drunkards

just browsing....

Right guys I've finished - I hope people find this useful.

Moving it to Technical

Ian C ClassOne, or Homer if you think this is any good please feel free to FAQ it

Mike

Excellent writeup mate:)

is there supposed to be a difference between pic 3 and pic 4?

is there supposed to be a difference between pic 3 and pic 4?

I presume you mean the "end results" yes and no.

You'll notice some clown has moved by the drivers door.

The point is that with no fog on you get all four brake lights. with the fog on you get the two outers acting as brakes.

HTH

Mike

oh well - looks like I underestimated the need for this then

Mike

Mike,

Absolutely fantastic write up i will be doing this in the next few weeks as my electical skill are non existant! I appreciate it even if no one else does

I think it should be moved to the FAQ

Will this allow the MOT to pass, as there are two lights used for the fog lights and also as there is no indications of the fog lights being on, on the dash board.

Will this allow the MOT to pass, as there are two lights used for the fog lights and also as there is no indications of the fog lights being on, on the dash board.

Use a switch that lights up, job done.

Excellent...

Can you tell me why you have used 2 relays??

Anyone tried running this setup with an alarm that uses remote start?

Can you tell me why you have used 2 relays??

The relays are there to trick the blown bulb circuit.

I assumed that there are 2 because either;

- it's easy to calculate what 2 resistors will 'look like 2 bulbs to the blown bulb circuit, and/or

- 2 will help to dissapate the heat better than 1

Anyone tried running this setup with an alarm that uses remote start?

I haven't, but why would the fog lights affect an alarm/remote start?

 

I haven't, but why would the fog lights affect an alarm/remote start?

I think it's something to do with the way the Clifford checks to see if the car is in gear?

http://www.mkivsupra.net/vbb/showthread.php?t=131173