After a kind recommendation on my last thread with my endless foglight switch question, could anyone recommend a diode suitable for the below application - and let me know if this is going to work (I know nothing about electrics).
Rescued attachment foglights.JPG

Why does it need diodes for a single bulb foglight/rear hazard ? If you want the foglight/rear hazard to only work on dipped beam just run a wire from the dip relay to the fog switch.

[Edited on 5/7/10 by Peteff]

As above, if you look at the IVA manual there is a table of conditions which must apply. In all of them the fog is only on when the dipped is also on, so just take a feed off that?

its got to work on dip beam and full beam so I need the feed to the switch to be fed from both relays. It just shouldn't work on sidelights.

It appears the best I can get without diodes is for the switch to operate during dip and flash.

Mine passed with the fog running off the side lights feed. The side lights stay on with dip and main tho.
Do yours?

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Originally posted by Doofus
Mine passed with the fog running off the side lights feed. The side lights stay on with dip and main tho.
Do yours?

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I do apologise... My column switch mechanically locks out the fog light switch so it only comes on with main or dip. Even though the feed is from the side lights.

if someone could advise on the questions ive posted I'd be very grateful.

This is basically the last thing keeping my car off the road and its getting a bit frustrating.

ETA: Ah, I see the problem now doofus, my switch is separate.

[Edited on 5/7/10 by cd.thomson]

Your dip beam should stay on when the main beam comes on. Ergo, just feed the fog lamp switch from the output of the dip beam relay.

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Originally posted by BenTyreman
Your dip beam should stay on when the main beam comes on. Ergo, just feed the fog lamp switch from the output of the dip beam relay.

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A 25 watt fog lamp should draw around 2.1 amps. This is rated for 3 amps or this is rated for 6 amps.

Yeah it will fail if it goes off with the main.

You must have the same stalks as me, (I have the sierra fusebox too) and when you hit main on, the dip relay feed switches off so I overcame it the way you drew it above.

I did reccomend the diode too in my original post to you a few days back:
LINK to original question

Maplin UK59P cost about 80pence each

HTH
Stott

Oh and the main will come on with the dip in a 'flash' operation but the dip is switched off in 'main' operation to prevent the filaments burning out in H4 bulbs, this is almost always the case. The exception is where the vehicle uses separate bulbs, say a H7 and a H3 which can both remain lit when main beam is on.


[Edited on 5/7/10 by Stott]

[Edited on 5/7/10 by Stott]

Hope you can follow this ( using my phone to post )


-----DIP-------------->DIODE>---------|
---Main-------------->DIODE>----------|--------FOG SWITCH ----------FOG RELAY / LAMP----


RD

Do it with a 5 pin relay.

Pin 86 earth
pin 85 main beam and linked onto pin 87
pin 87a to dip beam
pin 30 to fog light switch

job done - circuits kept seperate - and no diodes to blow

You will need to confirm with a real auto electrician but surelly a change over relay could feed from both dipped and main to the switch and then to the fogs

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You will need to confirm with a real auto electrician but surelly a change over relay could feed from both dipped and main to the switch and then to the fogs

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I posted from my phone in a dodgy area so my reply hit after you posted.
Yeah

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I posted from my phone in a dodgy area so my reply hit after you posted.

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As above - use a 5-pin relay, you don't want to be messing with diodes. Here's a diagram so you can see how it works:
Rescued attachment Fog relay.jpg