I finally have my C7 - fog light question

Eurovettes

Supporting vendor
HI to all - I finally after 4 months on route to UK I have a C7 (long story) - its an ex UAE car and is therefore an EXP rpo BUT - it is not like the UK spec cars with a rear fog stalk and setup. to comply with IVA and MoT I need to add a rear fog.
What changes have people with USA spec cars made to make this happen??????
I am wondering if the wiring is in the car for EXP models so maybe changing the stalk to the rear fog type will magically work !!!!!!
any one got actual experience of adding a rear fog??

Also interestingly the sat nav thinks the car is in Dubai (ha not much use here in Uk me thinks)

cheers ......Keith
 

Chevrolet

CCCUK Member
HI Keith, Suspect Keith C7 and Stingray (US spec cars) can help you on that? Think you need side repeaters in the front wings/fenders for the IVA too? On KeithC7s car they were nicely placed in the side vents. Cheers/Peter.
 
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UKBeancounter

Committee Member
Keith,

Wiring is not in the Loom already, the Euro cars have a separate loom from the US/EXP ones. I used a fog toggle switch on the panel to the left of the wheel where the mirror/HUD switches are, and bought some converted LED rear reflectors from Corso Motion. Chevrolet Corvette C7 POWER LED rear bumper reflectors in OEM Housing, 14 15 16 17 18

Paul at Lincs corvette sorted the wiring at the same time as the Euro mirrors with side repeaters you shipped in for me from Ecklers were added.

Others I have seen have added an LED fog in the middle of the number plate, but my personal view is the reflectors above give a better finish as they are based on GM reflectors.

Jason
 

Stingray

CCCUK Member
Federal cars have two reversing lights, one on each side. I believe Euro cars have one reversing light (on the nearside) and one fog light (red bulb in the offside reversing light position).

My car (Federal import) has two reversing lights and the fog lamp was added by arranging some red LEDs in the grille of the off-side lower rear valance. The switch is a small switch (with obligatory tell-tale) added to the left of the steering wheel, down near the rear hatch opening button.

My side indicators were similarly organised by arranging some amber LEDs in the grilles of the front side vents. I'm not aware of any other electrical changes.

Satnav (and radio) can be converted by some people in Sweden if that's considered desirable. The alternative is to just stick a TomTom in the central dash cubby - i.e. behind the electrically opening screen. There's a USB in there for power.
 

Eurovettes

Supporting vendor
thanks guys - where do you take the live feed for the rear fog - has to be on dip beam headlight circuit and has to reset when ign off (for IVA).
I have the little shutoff circuit board - just need to get where to take the feed from
I was considering removing rear bumper cover to utilise the high level brake light as rear fog
OPINIONS PEASE????
 

Oneball

CCCUK Member
thanks guys - where do you take the live feed for the rear fog - has to be on dip beam headlight circuit and has to reset when ign off (for IVA).
I have the little shutoff circuit board - just need to get where to take the feed from
I was considering removing rear bumper cover to utilise the high level brake light as rear fog
OPINIONS PEASE????

IVA says fog light needs to be between 250-1000mm from the ground.
 

FIVE RED

CCCUK Member
thanks guys - where do you take the live feed for the rear fog - has to be on dip beam headlight circuit and has to reset when ign off (for IVA).
I have the little shutoff circuit board - just need to get where to take the feed from
I was considering removing rear bumper cover to utilise the high level brake light as rear fog
OPINIONS PEASE????
Hi Keith, I personally know of a US C5 where the third brake light has been used for the fog lamp, no issues with MOT's in 13 years.
Hope this helps.
 

Eurovettes

Supporting vendor
yes the hlbl is under the height limit and would do the job I think. Rear bumper will come off this weekend

I do need to know where to take the live feed from in the dash - dont have wiring diagram yet
 

Stingray

CCCUK Member
Can't help with where to splice the live feed.

I'm sure IVA is tougher than MOT on all the electrical requirements so I don't see how you'd be able to use the centre stop lamp as a fog. Why not copy Euro cars and re-purpose the offside reversing lamp position with a red bulb?
 

Custom exotics

Well-known user
Dual wire the rear reverse lamp units maybe and add some white/ red switch back bulbs as for picking up wiring mate you might find you have to run to headlamp and pick up of actual dip beam bulb wiring as most modern headlamp switches control the lamps through the can hi and lol system to the bcm
 

Oneball

CCCUK Member
By the way - as you

Good point. Picking up close to the actual lamp should side-step that issue.

No experience on Corvettes but experience of fitting trailer wiring shows that doesn’t work for most LED rear lights as the CANBUS signal is all the way to the light unit where an ECU then decides if the signal is for brake or tail light. Hence you need to use the headlight signal or have a trailer ECU.
 

Stingray

CCCUK Member
I've just been out have a look at my car and the CAN issue having been floated it looks to my eye very much as though the trigger has been picked up from the front, left headlamp. On the images you can see that a "skinny", serrated conduit appears to have been clipped on with black cable ties alongside the original wiring loom.
 

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Roppa440

Well-known user
The C7 I just bought has a fog light switch fitted but does not do anything.
Hopefully the wiring is there somewhere. But where it was going to on the rear bumper I don't know....
 

Roppa440

Well-known user
I just found this in one of the rear ducts. Could be an LED strip?
What is the best way into there to investigate? Does that grille pop out of do I go in via the rear wheel arch?
 

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Roppa440

Well-known user
Well I popped out that plastic grille and indeed that is a red LED array in there and it is wired for a fog light.
However it is not getting any power and anyway it's not really a very good solution so going to replace the bumper reflectors with LED loaded versions.

But working out why it's not getting any power is a bit tricky. It seems very over-complicated.

On initial investigation it looks like a feed from the drivers side headlight runs to a relay in the footwell.
Why you would need a relay to power 12v LEDs I can't think?

The fog light switch fitted to the dash has THREE wires to it. Red, Blue, Black.
Again I can't figure out why.
Surely you just need one live from the headlight into the switch and one out? The ground points don't need switching?

I have got nearly a year before the next MOT so in no rush to sort it. Think I will take the front and rear bumpers off during the winter and just start from scratch with this.
 

Stingray

CCCUK Member
Three wires - don't forget the rear fog light switch needs a tell-tale indicator lamp, so requires it's own earth as well as the "in and out" to the rear fog lamp.

The relay could be there either to protect the main circuit against glitches or to make sure you don't get a "lamp failed" warning on the DIC because the current drain will be wrong.
 
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