Thursday 19 May 2016

R33 Rear Fog Lights

There was a time before I started recording my thoughts and musings (Sometimes even tidbits of information that actually are useful (but only by accident)). Forums were much bigger back in the day but now social media 'is where it is at'.
Not got Facebook? Then your stranger than me! The only problem I find with Facebook is that people answer with half the information, it could be that they are on their phone, but answers like "buy some diodes" just ain't going to cut it.

Whilst I am on my hobby horse, will gallop it around a bit.. People, if your drunk or just plain stupid, don't post!

Anyway, I saw a few questions popping up about rear fog lights on a R33 (this is a British orientated thing, "cor blimey Guv' it's a real pea souper") Ahem.. Anyway.. In the UK we have to have a bright rear fog light... for when it's errm foggy oddly enough. True, it's one of those strange items that seemingly few people actually know how to actually use, a magical switch that once turned on never gets turned off (a real pleasure to drive behind). As a legal requirement all imported Skylines have to have them. Usually as part of the SVA test (Single Vehicle Approval) a cheap lens is bolted to the back of the car.

Not that there is anything wrong with this as such, but it does look a little odd. When I first had my car I physically removed it and would bolt it back on when it came time to MOT. However hardly a permanent fix and a bit of a pain in the butt remembering where I had left it.
There are options for a more permanent solution, these include simply wiring a switch to your reversing light and painting the bulb red, or wiring to the inner brake lights so that they come on at the flick of a switch.
Obviously painting a bulb and loosing a reversing light is far too simple and just not cricket. So lets look at the other more complex and satisfying version. Doing this modification does not affect how the brake lights function (you still have all four). It is also the more aesthetically pleasing, does not interfere with any other function or look out of place.

Ok my blathering is over, onto the main course...

Skyling R33 GTS - GTR Rear Fog Light Guide. 

You will need
4 x 1N5400 3A Silicon Rectifiers (Maplins part) at £0.59 each
1n5400 diode

Solder or blue crimp connectors (and a decent crimper)
A screwdriver (to stab your hands with)
I am not going to be all clever with wiring diagrams, those are for people that want the rest of the world to see how jolly clever they are.
Instead I shall delight you with the basics on how it is actually done. With thanks to D.O.A. who originally shared this information.
Remove trim, you should be able to work this out yourself. However be careful when pulling out the plastic surround around the latch area as it is fragile and will crack. there are two push clips located centrally each side of the latch and they don't let go easily (you have been warned). Everything else you should be able to cope with.
So get hold of your diodes, you will need two for each side (remember we are wiring both inner brake lights, you could do one.. but that would be pants). Assuming you are using crimp connectors, crimp one end of two diodes into a connector making sure that the silver band on the diode is closest to the connector ( If you get it round the wrong way it will not work as the diode is a one way 'valve' which electricity flows). Crimp two more connectors on to the other ends of the diode ( These will be the feeds in ).
Now we can connect the wires to the diodes. On the car, cut the green/yellow brake light wire to the inner brake light making sure you leave a good length to play with . Connect the green /yellow wire coming from the light bulb holder to the crimp with both diodes in it , Then connect the other end of the cut green/yellow wire to one of the diodes ( This will power up the brake light as per normal). You will be left with one more connection to diode to be made, this is the feed from the fog light switch. For this you will need to run a joining wire from the left hand light unit to the right and then on up through the car to the dash (if you don't already have a switch wired).

Autographs are extra

If you need a switch in the dash, make sure its a 'tell tale' (one that lights up to say it is on) All you need to do is find a good 12v feed to power up the switch and connect it to the power in pin, connect the wire you have run through the car from the rear clusters to the power out pin then run a wire from a good ground up to the earth pin on the back of the switch.


  1. I'm on the same path w/ my Vspec II (32). Is this process the same when I'll make one of my reverse lights as rear foglamp? Planning on tapping it on one of the tail lights "park light" function.

  2. Saw these kinds of diode online too - 1n4001, 1n4002, up to 1n4007. They're different from the ones you used right?

    1. To be honest... I can't answer if the ones you found are different. Although the link still works for supply in the UK.


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