Roof rack earth

Would the roof rack frame be suitable for an earth for some work lights?
I would test it but the roof rack is in the garden at the moment.

I suppose it depends on the electrical contact between the roofrack and the vehicle structure. If it's part of a roll cage one would expect metal to metal contact all the way down to the chassis, but if it's merely clipped on to the gutters you've got paint and possibly a rubber pad, and then all then contact (or lack of it) between the body panels and the chassis so it might not work too well. If the roofrack spends a lot of time in the garden there's likely to be an additional layer of moss, slugs, woodlice, leaves and rust between it and the Land Rover, even when it appears to be clamped on tightly.

To be honest it's usually on the Land Rover but took it off to seal up the roof. I used to run the earth through the air vent and use a roof to side panel fixing bolt, maybe I shall do something similar again.

Drill and tap a 4mm hole in the roof rack.
Drill and tap a 4mm hole in the body/roof.
Join the two togther with a suitable, 2mm, 14A rated wire.

miktdish said:

Drill and tap a 4mm hole in the roof rack.
Drill and tap a 4mm hole in the body/roof.
Join the two togther with a suitable, 2mm, 14A rated wire.

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That's a better idea, already have nuts and bolts holding some of the cross bars on, will be able to utilise one of those.
Many thanks for the idea.

Anaconda said:

That's a better idea, already have nuts and bolts holding some of the cross bars on, will be able to utilise one of those.
Many thanks for the idea.

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Just use twin core cable? That’s what I have done for all of mine. Rear work lights, roof lights, bullbar lights. All have the power supplied by twin core so the earth is the. The same one the relays use to work. Chances are wherever you have got your power supply and relays will have a far better earth than the end point where the light is.
I took it a step further and my earth is the bus bar at the top of the auxiliary fuse board that supplies everything with power. So I have fuse box and relay box in the battery compartment next to each other. With all weathers for everything additional also back to the battery

Definitely not.
Run a decent wire earth to the chassis.

Dead Badger said:

Definitely not.
Run a decent wire earth to the chassis.

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Why not ?

I have less than less than 0.1 Ohms at the roof above the back door and the rear 1/4 panel (by the rear lamp 'triangle') to the negative terminal on the battery.
Very similar to the chassis, bulkhead and engine.
The interior light is earthed to the roof and the rear lamps are earthed to the tub.

dag019 said:

Just use twin core cable? That’s what I have done for all of mine. Rear work lights, roof lights, bullbar lights. All have the power supplied by twin core so the earth is the. The same one the relays use to work. Chances are wherever you have got your power supply and relays will have a far better earth than the end point where the light is.
I took it a step further and my earth is the bus bar at the top of the auxiliary fuse board that supplies everything with power. So I have fuse box and relay box in the battery compartment next to each other. With all weathers for everything additional also back to the battery

View attachment 325980

View attachment 325981

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I had also considered using twin core cable, might even have some already which would be a bonus.