I have Cortina Mk 4 stalks in my kit car (Marcos Martina).

Can anyone tell me please if the headlghts are  turned on without the ignition being turned on (ie permanent 12v feed)?

Thanks

John

5 hours ago, jgbff7 said:

I have Cortina Mk 4 stalks in my kit car (Marcos Martina).

I'm jealous, that is a fine looking car...

5 hours ago, jgbff7 said:

Can anyone tell me please if the headlghts are  turned on without the ignition being turned on (ie permanent 12v feed)?

Yes.

On the Mk4 Cortina the headlight switch was a constant live. The headlight switch always had a permanent feed. I do seem to recall that on later Mk4 and the Mk5 the actual headlights were fed via a relay which only allowed the headlights on when the ignition was on, but the switch remained live.

Thank you both very much. Here is a photo of my car. I just like the shape. The Martina was designed to have a single donor, a Mk4 Cortina.

The lights have been quite a saga. I could not get proper brightness and I suspected poor connections in the fuse box. So decided to rewire and fit halogen bulbs and relays. The 30 terminals on both relays get 12v direct from the battery, with a 30 amp fuse in the line. The original main and dip switch then provide the trigger to 85.

So, with the ignition off and the light switch two clicks up to headlights, I get a click from the relevant relay as I  go between main and dip on the left hand stalk.

But I asked the question to ensure I had the wiring correct as the lights work with the ignition off. I believe the modern trend is that only the sidelights are wired to be activated with the ignition off.

My understanding is that whilst the Mk3 had a relay the mk4 and 5 did not (apparently the workshop manual is incorrect on this point). But of course with kit car it is difficult to know what the builder did.

I am grateful to know that my improvement is working properly. Certainly the lights are a huge improvement.

By chance I am watching a Wheelers Dealers where a wiring issue with a VW has been solved by looking at a VW forum. Perhaps the internet is not all bad....

Thanks to you both

John

20 minutes ago, jgbff7 said:

My understanding is that whilst the Mk3 had a relay the mk4 and 5 did not

My apologies, just had a look at some old schematics. Yes you are correct about the Mk3 having a relay system, in fact it was quite clever. Depending on whether the ignition was on or off, the indicator stalk used to control the left or right sidelights so they could be used as parking lights.

The Mk4 did in fact not have any relay and the headlights were controlled directly via the light switch. Just to confirm the switch was always live, fed via a fuse directly from the battery positive.

The Mk5 got a little more complex, as this was at a time when 'Dim-Dip' was being trialed and some models incorporated a 'Dim' relay for the lights.

So in conclusion The Mk4 had the simplest system 👍

Thank you. This raises an important point about fuses. There is a lot of stuff on various forums about putting relays into headlight circuits. The whole point of course is to get maximum power to the lights so they shine properly, and this is done by taking the feed directly from the battery.

But this must be fused as there is no other protection for the wiring. It is interesting that in the Mk 4 the live to the switch was fused. 

The other reason for relays is to relieve the strain on the switch. The Mk 4 had that strain as there was no relay.

In my case the builder had put a relay on the main, but not on the dip. But it was wired incorrectly. Power went to 30, but 87 went back to the white in the fusebox instead of to the lights.

But all is well in the end and permanent power to the switch energises the approprate relay and we have light.

John