Factory D2 Foglight circuit

[MatthewThompson]

Is the factory circuit robust enough to run a bigger set of driving lights on the brushguard?

My truck came with a gaggle of 55W 8" lights on the bar/rack that were in various states of decay. I'm in the process of gathering the best parts from the lot and assembling a pair of decent units. I'd like to run these on the factory circuit if it's going to result in anything but a fire-based disaster.

I'd prefer to go Lightforce or equivalent, but the power company would prefer I send the money to them instead.

 

[jgdisco2]

they will work with the factory fog harness...please note that your offroad lights wont work when you turn your brights on, i just used the switch and wired it direct to the battery so i can turn them on whenever i choose.

 

[MatthewThompson]

please note that your offroad lights wont work when you turn your brights on, i just used the switch and wired it direct to the battery so i can turn them on whenever i choose.

Thanks for the info. I'm OK with the driving lights working exclusive of the fogs. Roof lights and rear worklight will be on a dedicated harness/relays switched by extra stock foglight/rear foglight switches in the binnacle.

 

[Paladin]

I think you might have missed what he was getting at. If you use the foglight circuit to run your driving lights, the lights will turn off when you hit the highs, and come on when you put the main beams on low. Opposite of what you want. You want the driving lights off when you have the lowbeams, and on when you hit the highs.

Also, I wouldn't run anything high wattage on the factory circuit. Use a relay an proper wiring. The factory wiring is marginal with the 35W bulbs as it is.

 

[Rovertrader]

I think you might have missed what he was getting at. If you use the foglight circuit to run your driving lights, the lights will turn off when you hit the highs, and come on when you put the main beams on low. Opposite of what you want. You want the driving lights off when you have the lowbeams, and on when you hit the highs.

Also, I wouldn't run anything high wattage on the factory circuit. Use a relay an proper wiring. The factory wiring is marginal with the 35W bulbs as it is.

agreed

 

[jgdisco2]

I think you might have missed what he was getting at. If you use the foglight circuit to run your driving lights, the lights will turn off when you hit the highs, and come on when you put the main beams on low. Opposite of what you want. You want the driving lights off when you have the lowbeams, and on when you hit the highs.

Also, I wouldn't run anything high wattage on the factory circuit. Use a relay an proper wiring. The factory wiring is marginal with the 35W bulbs as it is.

yeah thats exactly what i was referring to!

 

[MatthewThompson]

Little wonder I was misinterpreted, what I wrote in my reply made no sense!

High/fog operation will be mutually exclusive. Works for fogs, not ideal for driving lights. Agreed, noted and sustained. :snorkel:

 

[Paladin]

Now I'm confused. What is it you want to do?

 

[fishEH]

Why don't you just wire them independently of the headlamps and use the factory switch. I know they had good intentions, but personally I don't need Land Rover telling me when I can and can't use my fog/driving lights.

 

[MatthewThompson]

Why don't you just wire them independently of the headlamps and use the factory switch. I know they had good intentions, but personally I don't need Land Rover telling me when I can and can't use my fog/driving lights.

This.

 

[Paladin]

I'm not sure you can rewire the factory switch. IIRC, it is a momentary, normally open switch. It doesn't latch. The latching function is done within the Body Control Unit. You'd have to make a flip-flop circuit to go between the switch and the relay.

 

[rovertech]

In the factory system the BCU input from the lighting switch is controlled by the IDM which is inside the interior fuse box. I wouldn't mess with it. If you want to use the factory wiring you would need to wire in a "latching" switch to close the ground for the front fog lamp relay. If you did that you could operate the front fog lights whenever you wanted.

 

[Paladin]

I forgot about the IDM, you're right about that. But IIRC, the IDM is just a dumb relay driver module, and the decisions are ultimately made inside the BCU.