Rear Fog light help

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nick
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Rear Fog light help

Post by nick » Wed Jun 20, 2018 6:18 pm

So my Freda came with a lovely flush fog light in the bumper, but it doesn't work.

Pressing the little fog light switch blew my headlamp fuse.

Ive taken everything apart and cant work out how its all meant to work.[

https://photos.app.goo.gl/bX6HsaUhHP1AKwr3A

Thats the photo of the switch in question, the little light comes on when it should.

https://photos.app.goo.gl/gCyhiGXLu5r1BrCz8

Having removed the switch there are 3 wires attached to it, ones earthed, one goes to the stalk and one wire seems to go under the door trim and under the flooring and I found it tucked into to the bolt that holds the rear door catch...

https://photos.app.goo.gl/6G9B126Hu3w1QguUA

My foglight has two wires and the wire on the bottom is the one I traced back.

Any ideas on what I'm meant to do next.

You lot are all going to be at the Bash actually so I hope someone actually reads this :D
Roy748
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Re: Rear Fog light help

Post by Roy748 » Wed Jun 20, 2018 7:12 pm

Hello.
In most cases a blowing fuse is due to a short in the circuit somewhere, in that the live is shorting out with the earth.
If you trace the 3 wires from the switch you should find one going to earth one coming from a live source which from the sounds of it is the head lamp wire and the other, which will be live coming out of the switch when turned on, going to the fog light. Firstly trace all wires and look for any damage in the cable which could cause a short.

If you have a volt meter you can check the live supply is first going to the switch by removing the wire from the head lights that goes to the switch and placing the red volts meter probe to this wire and the black volt meter probe to a good earth such as a bolt attached to the bobywork. With your lights turned on you should get a current showing on the volts meter.
Next reconnect the head light wire to the switch and then disconnect the live wire which goes to the fog light, turn on your lights and then turn on the fog light switch. You should again see a reading on the volts meter. If not then the switch is faulty.
Finally if both the above show a reading of around 12V you need to disconnect the live wire at the fog light and again check with your lights on and the fog light switch turned on to check the supply isxreaching the fog light, again you shoukd a have a reading of around 12V.
If you do then it's the fog light itself which is at fault, which could be a bad earth connection or corrosion on the electrical connectors.

If you dont have a volts meter Try running a new live to the switch, ie remove the live supply wire coming from the head lamp.
Safest way to do this is to run a wire with an inline 5amp fuse fitted directly from the positive terminal on the battery to the switch. Remove the wire that feeds the fog light. As you want to isolate the switch at this stage.

Turn on the switch, If it blows the fuse again it's possibly the the switch at fault. If it does not blow the fuse connect a new piece of 5amp wire from the switch to the fog light live wire and test again.
This process just cuts out each length of existing wire with a new one which should help to identify if its a wire fault.
I should say first mind, check your earth wire from the switch and fog light are in good condition and have a good clean connection to a metal part of the body.

Looking at the switch photo you seem to have two wires going to one pin, each wire should have its own pin, live in, (turn switch on) live out and an earth wire pin.

Hope that helps
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nick
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Re: Rear Fog light help

Post by nick » Wed Jun 20, 2018 7:30 pm

Thanks for the reply, ive just done even more research.

So could the live wire to the fog light being earthed cause the fuse to blow?

Two wires from the fog light, will one connect to the live wire and one be earthed? how do I know which ones which?


There is only one wire in each pin btw
TheLongRoad
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Re: Rear Fog light help

Post by TheLongRoad » Wed Jun 20, 2018 8:00 pm

Have you changed the bulb? If the filament has broken it can arc across causing fuse to blow. Next have a look where the cables from the fog light in the bumper pass through the grommet into the inside of the vehicle- they could be damaged and causing the fuse to blow.

Take the bulb out and turn fog switch on. Can you get a live in the fog lamp? Assume the correct fuse rate was fitted?

Hope some of this helps.
2002 Friendee 2.0 ltr Petrol.
TheLongRoad
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Re: Rear Fog light help

Post by TheLongRoad » Wed Jun 20, 2018 8:03 pm

If you have a circuit tester - little screwdriver thing with light in handle, connect the croc clip to an earth and the use the screw driver end to prob each wire in turn. The live will illuminate your tester.
2002 Friendee 2.0 ltr Petrol.
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nick
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Re: Rear Fog light help

Post by nick » Wed Jun 20, 2018 8:30 pm

So the fog light wires must have been cut.

I have two wires coming from the fog light which are just dangling free

A live wire coming from the front fog light switch which for some reason was bolted into the chassis.

Ive unbolted it and its just on the carpet now, its not causing any problems and no blown fuses.

So i think I just need to connect that live wire to the fog light somehow? I was expecting two live wires tbh and its thrown me.
Roy748
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Re: Rear Fog light help

Post by Roy748 » Wed Jun 20, 2018 8:33 pm

Yes a live wire going direct to earth will blow the fuse. The earth wire from the switch should go direct to an earth, same is true of the earth wire in the fog light.
Follow both of these wires to establish this.
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nick
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Re: Rear Fog light help

Post by nick » Wed Jun 20, 2018 8:47 pm

right, Think im getting to the bottom of this, so is there a way to tell which wire is which coming from my fog light?

What kind of idiot just takes the live wire and screws it into the body to get it out of the way.
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nick
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Re: Rear Fog light help

Post by nick » Wed Jun 20, 2018 8:49 pm

Roy748 wrote: Wed Jun 20, 2018 8:33 pm The earth wire from the switch should go direct to an earth,
Yep this all seems ok,
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nick
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Re: Rear Fog light help

Post by nick » Thu Jun 21, 2018 10:36 am

For those of you excitedly watching this thread.

I have done it. I Now have a working fog light again.

Thanks for all the help :D
TheLongRoad
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Re: Rear Fog light help

Post by TheLongRoad » Thu Jun 21, 2018 11:21 am

Smart, job well done and now you know more about the workings of the Bongo. (bet you are hoping for a foggy day :lol: )
2002 Friendee 2.0 ltr Petrol.
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nick
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Re: Rear Fog light help

Post by nick » Thu Jun 21, 2018 11:39 am

not as much as Im hoping it passes its MOT :wink:
TheLongRoad
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Re: Rear Fog light help

Post by TheLongRoad » Thu Jun 21, 2018 11:59 am

We all worry about the MOT [-o<
2002 Friendee 2.0 ltr Petrol.
Roy748
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Re: Rear Fog light help

Post by Roy748 » Thu Jun 21, 2018 3:58 pm

Well done.
Might be worth investing in a volts meter or screwdriver type 12V power tester, as this will make future electrical diagnosis much easier.
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