Wiring spot lifts with side lights in aswell.

Hi there folks,
I put some spot lights on the front of my defender from the show at Peterborough, I was going to wire them in tomorrow, my knowledge of electrics on vehicles is not huge so was just after some advice on the best way to go with this one. I was going to wire the main beam lamps through a relay with the feed to the relay picked up from the head lights and a main feed from the battery, and for the side lights am I ok to just pick a live feed up from the side lights on the front straight to the spot lights. I would be grateful of any advice or pointers as the best way to do this. Many thanks in advance. . . . EwdMucker.

So your spots have sidelights in too? If they're LED, what you've described sounds fine, probably ok even if they're not. Don't forget a fuse in the battery feed bit.

Yes, as long as you're not drawing to much current from the side lights, sounds like a good plan wiring then into a feed from the main beams.

Hi. The side lights are normal bulbs not LED. I forgot about a fuse on the main feed. Thanks.

what sort of wattage are the spot lamps?

Not sure. I have left the box at work, I'll have a look tomorrow. I was going to divide the watts by 12 volts to give me the current to find out what fuse I need, is that right . . .???

Yes.
But make sure the wiring is rated at least 1.5 times that figure.

Yep W/V=Amps +a bit for the fuse

If you are fitting spots, I would be inclined to put a relay on each of the headlamp and sidelight circuits.

Ok. Just to make certain in my head. Would you use a relay for the side light circuit and relay for the main beam circuit or do that for each side making 4 relays in total . . .??

Use a relay on the side light circuit and another one on the headlamp circuit, which makes two in total.
Both will also need to be independently switched via the relays, as you can't have them on all the time coz it's illegal!

And you have to have them switched so the main beam can be on without the spots. Apart from that what eccrine else said

Definitely do it via a switched relay, the sidelight wiring is made for the sidelights, if your sticking spots on it you will draw way to much current, possibly melt the loom and there goes your truck up in flames!

Personally I always keep any additional electronics on a completely separate circuit from the original loom, as said picking up a switching live for the relay is fine but I would use a complete new loom for the power supply

+1 make a new loom and just tap in for side and main in an accessable location and put the relays close to the taps so your new wiring adds the least risk to the factory wiring

... And don't forget to fuse them separately!

Nice one guys. Thanks for all the helpful info, it's much appreciated.