noob light wiring question

[ditch]

Just bought 4 cheapy spot lights for the top of my roll bar. They each have a ground wire which is attached to the base (metal) so they are already earthed. So if I wanted to run the 4 wires down into the engine bay somewhere, and for them all to run off the one switch inside the cab, what do I need for this?

Main questions are:

- What is needed? (A relay or something, I honestly have no clue)
- Where do I get a wire from to connect all the lights to for power?

Cheers.

[trr35l]

what size lights i mean now many watts each light eg 55watt or 100watt as this tells now much current to run lights now much current what size cable and fuse???

do not trust the shite earth on the lights just to body or roof rack of car run an earth from the batt to a common point and fix all earths to that just to make sure lights get full brightness

you will need at least one relay as most are 30amp that is a total of 360 watts if you have 4x 55 watt lights you may just get away with one (length of cable gives voltage drop and loses power and gives dull lights big cable less lose more light)

to wire relay it is power from batt on to 30 on relay
power to lights is off 87 on relay
power to turn relay on is 85
earth relay 86
fuse the power to relay number 30
numbers are standard on most relays these where read off a narva 30amp

good luck

[drivesafe]

Hi ditch, can’t add much to the advice given by trr351, right on the money but if you want a diagram of the wiring up driving lights, try this web site.

http://www.aulro.com/modules.php?name=F ... pic&t=5471

Cheers

[ditch]

Thanks for the help, would I get a relay from somewhere like Jaycar? Cheers.

[ozy1]

most auto parts places will have relays, your best bet is to use 2 30 amp relays, that are 5 pin, so the have all the connections stated above but it has an extra labeled 87 and 87A so you can run 2 lights off each relay, and off the top of my head, a 100W light draws around the 8 amp mark, i carnt be farked working it out properly, my head hurts already........

[DAZZ]

A relay with 87 and 87a is a change over relay. This relay can serve two functions. 87 will be live when the relay is energised and 87a will be live with the relay de-energised. This is not the correct relay to use. One with 2x 87 pins is what you need.

[kranked_dirt]

Does anything change when you have negitivly switched headlights? Also is there anyway to tell if you have this setup??

[drivesafe]

Hi kranked_dirt, check out the site I posted above. It shows how to connect driving lights to both positive and negative switched headlight wire looms.

Cheers

[kranked_dirt]

cheers drivesafe, had a look at that site, do you know why the relay needs to be wired like that? and how do you tell if you have negitavely switched headlights?

[ditch]

Well today I had some free time so I went to jaycar, bought 2 relays, a bunch of wire, a fuse and holder, and some heatshrink.

I wired my 4 spotties up, connected everything to the correct terminals, flicked the switch, and .... nothing. Checked the fuses, all fine. Double checked connections, seem fine. So what is going on?!?!

My wiring is featured in the picture below (comment on my great home drawing later )

Any ideas?

BTW all the spot lights are grounded. (Doesn't show it in the pic).

[drivesafe]

Hi ditch, the drawing shows that the only way the lights will operate is when your ignition is on and the switch you installed is on.

There is no apparent connections to your headlights.

If the lights still don’t work then the other thing to check is that your ground is actually an earth.

It’s always better to run a separate earth from high current devices like driving lights, all the way back to the battery’s negative terminal. This will guaranty that there is a correct current return.

[ditch]

Thanks for the reply mate. The lights aren't hooked up to the headlights in anyway and that's how I want it (provided it works!) because I just want to be able to turn them on when the car is on and when the switch is on.

I guess I'll have a mess around with the earthed wires, see if anything I do with those helps eh. I'll let you know how it goes.

[ditch]

Ok what the fuck, just went out to have another mess around with the wires, and before I did anything I thought I'd give em another try, and now they seem to be working fine?!?! Fucking weird, this sorta shit happens to me all the time!
Oh well, thanks for the help!

[84ZOOKSTA]

one thing to watch out for it the grounding of the lights. if they are connected to the bolt that connects them to the roof rack make sure you have a good earth. normally the roof rack only clamps on and will not make a good connection at all. you might not notice any problem with them now but you wait till the water and corosion start affecting the bolts and where the rack attaches to the roof. the way to fix this is by running a ground wire to every light.



Cheers
Simon...

[TRobbo]

From your earlier posts it sounds like your a newbie to this - so please forgive me if I state the obvious here.
To check your wiring a test lamp is a great investment. Hook it up to the negative of your battery and stick the pointy end on the positive terminal -have light and your already to start checking your power.
If there is no power at your lights then start checking for power at the relay. Stick the pointy end on pin 30. If you have light this is working fine - If not the problem is in the connection to you battery (perhaps a fuse).
Next check your switch power (ensure ignition is on). Turn the light switch on and stick the pointy end on pin 86. Have light you have power - if not the problem is from your switch or where you are picking up your switch feed from. If you have power check to see that you are also getting power out to pin 87 and sort the problem from there.
Next swap your test lamp around on the battery so that the aligator clip is on the positive terminal of the battery. Your then ready to start checking that you have an earth on pin 85. No light - no earth.

This should be the basis for working out your problem. If it is intermittent then it sounds like a loose connection or poor earth.
Hope this helps.

[drivesafe]

Hi ditch and TRobbo, a word of warning, no matter what vehicle you have or plan to work on, I strongly recommend that you DO NOT use a test light on a modern vehicle as it could be fatal.

Using a test light on a vehicle can trigger the safety air bags and in the USA there have be a number of deaths as a result of test lights being used.

You can buy a multi meter for as littler as $15 so it’s not worth the risk.

[nicbeer]

Hi ditch and TRobbo, a word of warning, no matter what vehicle you have or plan to work on, I strongly recommend that you DO NOT use a test light on a modern vehicle as it could be fatal.

Using a test light on a vehicle can trigger the safety air bags and in the USA there have be a number of deaths as a result of test lights being used.

You can buy a multi meter for as littler as $15 so it’s not worth the risk.

Although it is a good idea. a hilux this age i do not think knows about airbags yet unless they are in the passenger seat.

[drivesafe]

Hi nicbeer, your vehicle may not have air bags but as all new vehicles are equipped with air bags, it would be prudent to get into the habit of NOT using a test light at any time and that way you are not likely to forget when working on, say, a mates vehicle that is equipped.

It’s a safety procedure that can most definitely save lives.

Cheers.