Discussion
Hi..
On latest Kitcar magazine I saw that some changes on the rear fog lamp switching regulations.
What are current builders doing , is the harness being modified or anything else?
I presume a latching relay and momentary switch will fix this....
Cbs offer some kind of relay too..
Tks and greeting to all...
Mark
On latest Kitcar magazine I saw that some changes on the rear fog lamp switching regulations.
What are current builders doing , is the harness being modified or anything else?
I presume a latching relay and momentary switch will fix this....
Cbs offer some kind of relay too..
Tks and greeting to all...
Mark
I started a thread on this in the Kitcar section.
I soon had an answer that this change in the IVA manual had now been scrapped, via email, to the test centres.
I don't thing the requirement will go away for good they probably just need to amend the wording.
My thread was about relays as I had been looking at how I could comply with the requirement. A latching relay will not work. I've drawn a circuit using a standard relay and a momentary switch which will work fine but if you wanted to switch the fog off again whilst the headlights are on you can't. However you would just switch the headlights off and back on again and the fog light would go off. I don't consider this to be too much of an issue.
I also have a circuit using 3 relays which in theory will work but I have not built a test model.
Steve
PS for those not aware, the new requirement was that in addition to the fog only working with the headlights it also had to go out when the headlights were turned off and not come on again unless actually selected.
I soon had an answer that this change in the IVA manual had now been scrapped, via email, to the test centres.
I don't thing the requirement will go away for good they probably just need to amend the wording.
My thread was about relays as I had been looking at how I could comply with the requirement. A latching relay will not work. I've drawn a circuit using a standard relay and a momentary switch which will work fine but if you wanted to switch the fog off again whilst the headlights are on you can't. However you would just switch the headlights off and back on again and the fog light would go off. I don't consider this to be too much of an issue.
I also have a circuit using 3 relays which in theory will work but I have not built a test model.
Steve
PS for those not aware, the new requirement was that in addition to the fog only working with the headlights it also had to go out when the headlights were turned off and not come on again unless actually selected.
CBS do a little module to achieve this.
It seems to be the most debated IVA subject for some time. I iva'd my car shortly after it appeared in the bible. My car was wired the traditional way and passed.
The examiner told me if the fog light came on with side lights then it would need to be changed. If it only comes on with dipped/main beam then nothing has changed.
As Steve says I would imagine in the next revision they will reword it to make it clear that it must switch off with the lights and not come back on again. So if I was building now I would change it. It would be a shame to fail IVA an something like this.
It seems to be the most debated IVA subject for some time. I iva'd my car shortly after it appeared in the bible. My car was wired the traditional way and passed.
The examiner told me if the fog light came on with side lights then it would need to be changed. If it only comes on with dipped/main beam then nothing has changed.
As Steve says I would imagine in the next revision they will reword it to make it clear that it must switch off with the lights and not come back on again. So if I was building now I would change it. It would be a shame to fail IVA an something like this.
Surly one DPDT relay to do this,
load from dip beam feed to latching relay.
Dip on (feed to fog circuit) switch on fog with momentary switch, energises relay which then latches with dip light feed.
drop dip beam, relay unlatches fog light out.
This does mean that you have to kill dipped beam momentarily to release fog relay though.
load from dip beam feed to latching relay.
Dip on (feed to fog circuit) switch on fog with momentary switch, energises relay which then latches with dip light feed.
drop dip beam, relay unlatches fog light out.
This does mean that you have to kill dipped beam momentarily to release fog relay though.
F.C. said:
Surly one DPDT relay to do this,
load from dip beam feed to latching relay.
Dip on (feed to fog circuit) switch on fog with momentary switch, energises relay which then latches with dip light feed.
drop dip beam, relay unlatches fog light out.
This does mean that you have to kill dipped beam momentarily to release fog relay though.
If you have to drop dip beam then you can do the same thing with a standard relay ie you don't need a latching relay.load from dip beam feed to latching relay.
Dip on (feed to fog circuit) switch on fog with momentary switch, energises relay which then latches with dip light feed.
drop dip beam, relay unlatches fog light out.
This does mean that you have to kill dipped beam momentarily to release fog relay though.
Steve
GtrMan said:
Thanks for all the info on this matter..
Steve is it possible to have a copy of this diagram please ? the 3 relay one.
Tks in advance
Mark
One relay works but needs headlight switched off if you want to loose the fog when you still have lights on.Steve is it possible to have a copy of this diagram please ? the 3 relay one.
Tks in advance
Mark
Three relay version probably works but if you held the momentary for too long it would drop out again.
Took me a while to work through the logic of it.
I've not built one yet to proove it works.
Steve
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