Mounting a 50” / 40 amp light bar to the roof

[AWo]

Where do you drive that you need a 40 Amp Lightbar? And in addition: on the roof? The worst position for having light for driving. 40 Amp ist needed if you need to look very, very far or drive very fast or both. But then the roof is far from being an ideal position. If you need the light for much slower offroad-driving, half and even less of this power is more than enough. If you drive in woods, forests, mountains (with trees and curves) you only blind yourself.

I'm in LED automotive lights, it's my job and I drove competitions and I work together with very experienced overlanders and Rallye Dakar teams. If you do not do competition on clear and almost plain surfaces, you do not need such a lightbar. Especially in a 12 V car. It may be fine for a 24 V truck.

Ever thought about, what wire diameter you need and that it sucks 40 Amp from your generator, leaving the rest with what amount of power...? In a Grenadier which in general has problems with batteries not fully loaded?

AWo

 

[Glen]

. . .
Ever thought about, what wire diameter you need and that it sucks 40 Amp from your generator, leaving the rest with what amount of power...?
. . .

If it's 12' from the battery / fuse panel to the lights and 12' back (3.7 m), a 40 A load at 14.2 V would require 6 AWG or 16 mm^2 wire (for insulation rated < 105° C). That's not impossible to deal with but definitely a large conductor.

 

[holto]

Iam looking at refining this as its the way our blacksheep lightbar is wired (roof outlet via "EXT3"),

I hope to have it piggyback a signal from the overhead "aux headlight" switch so i can dip it in conjunction withthe headlights to as firstly not to blind other drivers and secondly to actually conform with the Au ADR Rules if challenged.

View attachment 7927366
I believe it is tapped from the high beam circuit?



Iam assuming this is the switch in question?

View attachment 7927367

If so I imagine I could take the supply side of the EXT3 relay control switch and feed it from the "D_SW" signal?

BTW on the MY24 Au quartermaster the passenger side roof outlet is EXT2 and the drivers side EXT3, as there are no other roof outlets mike on the Wagon they simply have a single outlet on ea CCT.

so far i havent found the EXT2 or # switches in the wiring diagram,

OK, so further investigation from previous post,

so turns out the Aux switch would be a no go,

It is wired and functionally provided to be what seems the ability to turn the high beam lights on as an alternative to the stalk controls.

Aux High Beam Headlights -
Press switch to switch on. Car must be running.
Lights will activate when high beam is selected. In addition, NAS vehicles also need offroad or
wading mode activated.
Press switch again to switch lights off.

the "D_SW" contact grounds a signal to the BCM and from here the BCM providing all the prerequisites are met ( off road mode in NAF etc....) turns the high beam lights on.

the "D-LED" then comes back from the BCM to indicate that the function is on.

so in a nutshell this doesn't help my aim, still further investigation required, ATM looking like i might need to run another wire up to the roof console :-(


Alternatively i may be able to "borrow? one of the footwell wire feeds that i dont use if its easy enough to run a jumper acrosss to the BCM to intercept the high beam signal on AC08 or AC18?, then swap the other end on the headup to trigger the EXT lamp relay via Sw 2?

Anyway this is a medium to low priority need for me so will investigate further time permitting.