I have been trying to wire in a new illuminated fog light switch and blown three 15 amp fuses in the process. I have found which wires go to which colours now, unfortunately i dont have any back lights or fog lights now.
Please can anyone tell me what i have missed, i have checked the fuses, they seem ok, any ideas guys, what have i done wrong

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Exup

Maybe go through what you've done step by step, with photos, diagrams etc. if possible.
Did you just change an existing switch, or have you broken into the rest of the wiring.

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If at first you don't suck seed, try drier grain.

I have checked to see if i had any power coming from the fog light wires, no power. Checked drivers side fuses, plus passenger side and under bonnet, all fuses appear ok.

I have a illuminated fog light switch, which i had a problem with, but it's sorted now, this was going on in place of the original. Unfortunately after charging my battery i found out i had no power to the fog light switch.

All i have done is cut all the existing wires from the original fog switch.

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Exup

I have found the problem, a faulty 15 amp fuse' it looks ok, but it wont let current pass through.

Yesterday i went to a car electrical speciallist, he explained what to do to get the switch to light up, unfortunately am finding that it keeps on blowing fuses going by what he told me to do.

Can anybody tell me a easy sollution!!!

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Exup

I think I would go right back to the beginning, put everything back the way it was and remove the switch.

Then try and get the normal lights working again.

Presumably this is on a JDM car?

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GT4DC Events Co-ordinator
1996 ST205 UK

The original switch should have 2 connections. One will come from the main lighting circuit and will be live when lights are on. This will then feed into the switch, and the other side will then feed to the fog lights.
The illuminated switch should have 3 terminals. 2 of them will be a switch. the 3rd will be the ground for a bulb, the other side of which will connect to one of the switch terminals. The common terminal (goes to bulb and switch) should go to fog lights. The bulb only terminal should go to ground and the switch only terminal should go to the incoming live.
Alternatively, the switch may have 4 terminals - 2 for bulb and 2 for switch. In this case, wire 1 bulb terminal to the switch terminal which goes to the fog lights and wire the rest as above.

Would be easier with a diagram but I can't be bothered drawing, scanning, uploading to photobucket etc. at this hour.

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If at first you don't suck seed, try drier grain.

I will have another go @ this job later.

Thanks for your help.

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Exup

You also need to be sure that the switch is capable of handling the load. Single rear fog light will be 55w which is about 5Amps so you want at least a 6 Amp switch. If you wire up the rear brake lights using diodes (this looks much cleaner than having a light hanging off the rear bumper) then you will have 2 X 55w and will require a switch that will cope with more than 10Amps.

I have just had to replace my fog light circuit and I have used a small relay so that the switch does not see the full load. I have taken the feed to the switch from the lighting circuit so that the fog light can only come on when the tail lights are lit. This way my small switch can be used for dual fogs without melting and the fogs come on with the lights if the switch is at the on position!:wink:

I got a fog light switch from a Toyota Carina, it lights up front fog lights and back fog lights, two of these lights have been taken away from being brake lights. Im not sure about how many amps the switch will take, but had the car running and it appears ok, no burning or fuse blowing!

At a later date i would like to put in led bulbs, i suppose i will need a relay or diodes, im not to sure.

Will something show up on the speedo housing, how i stop a display showing up, (showing a blown bulb) is it a case of using diodes to fool the system as diodes work at a lower amps i beleive.

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Exup

The dual filament bulbs are normally 21W (2A ish) for the bright filament, so a total load of 4A. Most automotive switches should cope with this.

LED bulbs will take much less current so shouldn't cause an overload when you change.

The normal trick for adding fogs is to feed brake light signal through a diode instead of cutting the wire altogether. this will then avoid the lamp failure warning by lighting all 4 bulbs on braking. You will also need to feed your fog lamp signal through a diode to the bulb to avoid a back feed,

(diodes allow current to flow one way only)

If you need a diagram, I'll draw one & post it.

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If at first you don't suck seed, try drier grain.

A diagram would be much appreciated.

I have had a lot of problems just fitting the switch. I went to 2 auto elecrical shops, both were wrong about the switch, so i eventually sorted it my self!

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Exup

ok, a genuine back of envelope sketck . . .

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If at first you don't suck seed, try drier grain.

Thanks for your help.

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Exup

I should have known that really!

Just don't ask me to wire up your house. Oh wait, do, I need the work!