Reverse light & New Caterham Light Kit

[Jonathan Kay]

Yes, the logic can be modified with a common relay type.

But I hope that it won't be necessary if we can analyse the earth side of the new lighting kit.

Jonathan

[SLR No.77]

Just fit a relay, job done!

Edited to add ... a relay can be wired with input and output plugs enabling it to simply be connected into Ralph's loom between the existing reversing light wiring and the new LED wiring, without changing anything in either. The car wiring remains standard as does the new LED lighting and loom, much better if anything faults at a later date.

Stu.

[John Vine]

Hmmm...relay.  Neat idea, and no need to go poking about in the LED loom.

JV

[ScottR400D]

Jonathan, there are no instructions or diagrams with the kit just a reference to the video which isn't quite right for the current kit either, though not with regards to the wiring. 

[Jonathan Kay]

Thanks

Jonathan

[John Vine]

Edited to add ... a relay can be wired with input and output plugs enabling it to simply be connected into Ralph's loom between the existing reversing light wiring and the new LED wiring, without changing anything in either. The car wiring remains standard as does the new LED lighting and loom, much better if anything faults at a later date.

Yes!

JV

[Ralph]

Hi everyone

Relay sounds possible does anybody know where the feed from ignition is connected to the Green/Brown wire.

I had an of the wall thought, as the wire is constantly live when the ignition is on could I just wire a two terminal G/box swilch on that one wire?

Scott. I have attached picture of the unit with connection. I think the 3 wires a two live one for the reversing light and one for the numberplate light and the 3rd would be earth.

[OldAndrewE]

OK, I was forgetting that the unit also has the numberplate light and they obviously share a common earth which will be permanent so your original setup with a switched earth will not work.  For this unit you must have to switch the live to the reverse light.  CC's assertion that the kit will work for all models is a bit optimistic

[Jonathan Kay]

"Relay sounds possible does anybody know where the feed from ignition is connected to the Green/Brown wire.

"I had an of the wall thought, as the wire is constantly live when the ignition is on could I just wire a two terminal G/box swilch on that one wire?"

For the live feed to a relay you should be able to use any green wire from the chassis loom. I'd recommend that you test it first. Running two rear lamp circuits through it shouldn't be a problem as the current draw with LEDs is so low.

But I don't know what you mean by "the wire" in the second paragraph.

Jonathan

PS: You might like to add a note at the fuse box if you use a different live feed that has a different fuse.

[Jonathan Kay]

From #18 above:

"First disconnect the lamp unit and check whether the Green/ Brown wire from the chassis loom is connected to earth all of the time rather than only when the switch is closed."

I suggest that you check this to make sure that the switch and wiring are working correctly.

Jonathan

[Jonathan Kay]

"Relay sounds possible does anybody know where the feed from ignition is connected to the Green/Brown wire."

 

With your current wiring the Green/ Brown from the gearbox switch isn't a "feed from ignition". It's a switched earth.

 

Jonathan

[Jonathan Kay]

 

"I have attached picture of the unit with connection. I think the 3 wires a two live one for the reversing light and one for the numberplate light and the 3rd would be earth."

Thanks. It's the first time I've seen what this is like.

Is the other end of that cable in the reversing light/ numberplate unit? 

And is there an adaptor subloom that connects that connector to the original chassis loom?

Jonathan

[Ralph]

Hi Jonathan

Yes the end is connected directly to the new unit

No this connects directly with the new loom connector

no other connections and all the wires from original loom to the number plate light are redundant, 

According tp Caterham video this is for all models 

Ralph

[John Vine]

Re #32:

I had an of the wall thought, as the wire is constantly live when the ignition is on could I just wire a two terminal G/box swilch on that one wire?

If by "the wire" you mean the switched 12v feed (or, indeed, any switched 12v feed -- usually green), I think you're proposing the circuit at bottom right below:

This is the switch, and it might just be a straight swap, but you may not have the access hole in the driver's side tunnel panel that later cars have.  You'd need extra wiring, of course.

JV

[ScottR400D]

Just in case it helps this us the wire colours for that connector 

[Jonathan Kay]

"Is the other end of that cable in the reversing light/ numberplate unit? 

And is there an adaptor subloom that connects that connector to the original chassis loom?"

...

"Yes the end is connected directly to the new unit

No this connects directly with the new loom connector

no other connections and all the wires from original loom to the number plate light are redundant, 

According tp Caterham video this is for all models "

...

Thanks. But that second one sounds like a Yes.

Please can you add a photo of "the new loom connector".

Jonathan

PS: Thanks, ScottR400D.

[SLR No.77]

I'm sure this is being over complicated!

The existing reversing light should, within the unit, contain a green wire (switched ignition live, it might be another colour but should be green) plus a green/brown wire (earth return via gearbox). I'm going from memory here, but I see no reason to be accessing the tunnel, swapping the gearbox switch, looking for another ignition live, plus a whole myriad of other ideas if you already have the wiring you need!

This is why I modified John's diagram to add a relay, with the power for the relay coil being taken from the existing ignition live, which also then feeds the current for the new loom (post #25).

Unless there's a gaping hole in my thought process this should be a fairly easy fix.

Stu.

ps. I suspect Caterham's reference to "all models" refers to "all current models".

[John Vine]

...this should be a fairly easy fix.

Agreed.  A very neat solution and, combined with your suggestion of an intervening subloom, the front runner, I'd say.

JV

[Jonathan Kay]

Ralph, in case this isn't clear:

There are now three solutions being discussed in this thread. In no particular order, and as briefly as possible:

1 Change the gearbox switch to a two terminal live switched system. 
Buy and fit a new switch. Run a new live feed to it. Fit the new lights without modification.

2 Add a relay.
Buy and fit a relay. No changes to gearbox switch and wiring. Fit the new lights without modification.

3 Modify the earth wiring in the new lamp unit.
Identify and separate the earths in the new lamp unit and add a new wire for the reversing lamp earth. No changes to gearbox switch and wiring. Fit the new lights and wiring with that modification.

Jonathan

[ScottR400D]

Again for what it's worth this.shows that those wires change colour going into the new loom

Brown become red, white becomes black  

A

[Ralph]

Thanks Jonathan & All

I have decided to go with two pin switch, should have it by Saturday

I have undone some of the existing loom and removed the switch and found the live feed which is keeping the light on, so propose to use this Green wire as per the picture.

Is this to simple or am I missing something as you diagrams you have a two way connector 

Ralph

[Jonathan Kay]

With that solution you need a new live feed to the new gearbox switch, as you've shown.

But I'd use the existing Green/Brown wire from the gearbox switch to the new lamp unit. It will then be a switched live to the lamp unit.

Jonathan

[John Vine]

Re #46:

In essence, you're going from top left to bottom right in my wiring diagrams. So, as JK suggests:

1.  Disconnect the G wire from the 2-way and run it to the new switch.

2. Connect the original switched earth GB wire to the other switch terminal.

3. Connect the LED loom (single Green) and away you go!

JV

[John Vine]

Re #46:

I have decided to go with two pin switch...

I realize you've already ordered the switch, but you'll still need to lay a new 12v switched supply.  You could either extend the existing reversing-light feed (from the rear of the car to the gearbox), or take a spur off a closer existing 12v switched supply (a gauge, perhaps)

Thinking more about it, however, I have to say that Stu's idea of a relay (#42) is IMO a far more elegant and logical solution, especially when incorporated in a separate sub-loom.  As mentioned already, it would be a simple plug 'n' play installation, avoiding the need to modify existing wiring or replace switches, and could be removed at any time for fault diagnosis.  If it were my car, it's what I would do.

Here's a wiring diagram, based on Stu's idea:

The relay loom sits between the standard loom and the new LED kit. For the Econoseal connectors, you would need one 2-way male (ESC2M) and one 2-way female (ESC2F).

JV

[SLR No.77]

I like that John  

Stu.