Wiring spotlights

Submitted: Sunday, Sep 29, 2013 at 00:51
ThreadID: 104514 Views:13120 Replies:9 FollowUps:2
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Hello all, time for more noob questions.

I want to wire up some spotlights to my old 97 hilux. Seeing as I'm not so cluey when it comes to that sort of stuff I want to make it as simple as possible. I have a couple of questions to ask.

There is already a switch on the dash from some previous spotlights. Can I just wire up the spotlights through this switch and battery so it is a totally separate circuit that I control independently from the headlights?. If this is so, obviously I don't need to wire in a relay,right? Nice and simple. Are there negatives to wiring spotties on a separate circuit like this or is this the norm?.

Thanks all
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Reply By: Member - John - Sunday, Sep 29, 2013 at 01:09

Sunday, Sep 29, 2013 at 01:09
Grant, if you have to ask the question then I would suggest you get an Auto Electrician to wire them in for you. Wiring direct from the battery through the switch is a recipe for disaster. Also, spot lights have to be wired such that they can only be active when high beam is on. Good luck.
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AnswerID: 518879

Reply By: Member - PJR (NSW) - Sunday, Sep 29, 2013 at 07:53

Sunday, Sep 29, 2013 at 07:53
Hi Grant

I totally agree with John. Get someone to do it for you. How do you know that the switch wont melt and stuff up something behind the dash. Oops a fire! And I am 200 kms from anyone.

Don't touch it Nigel.

AnswerID: 518880

Reply By: Member - TheFox3305 - Sunday, Sep 29, 2013 at 10:50

Sunday, Sep 29, 2013 at 10:50
To be legal they must be linked to the high beam circuit.

To be safe in terms of not setting fire to your car, the circuit(s) must be fused. Depending on the current draw of the spotlights, you should use a relay.

Hella and others sell a wiring loom for spotlights. Comes with wire, relay, fuses, switch, instructions. Try Supercrap, Repco and similar places.

The problems:
- is each vehicle is different and you may need some help or a wiring diagram to pick up the high beam wire.
- if you want a good installation, you need good crimpers

Using a little bit of brain power you should be able to substitute your switch for the supplied one.


AnswerID: 518890

Reply By: Hairy (NT) - Sunday, Sep 29, 2013 at 11:28

Sunday, Sep 29, 2013 at 11:28

Yes you really should run them through a relay and they need to be activated by your high beam switch to be legal in every state I know of.
But......it really is pretty simple to do.
have a look at this
wiring link
There are plenty of people on here can answer any questions if you have trouble.

AnswerID: 518892

Reply By: allein m - Sunday, Sep 29, 2013 at 14:11

Sunday, Sep 29, 2013 at 14:11
I'm not so cluey when it comes to that sort of stuff

so you admit you do not know too much good start now go that extra step and get some who knows what to do

I got a professional to do my Mitsubishi magna

he installed spot lights and converted the main lights to HD

magna are totally different than most you wire your power to low beam so that they work on high beam only

he also put a relay onto my light fuse box and a extra HD relay onto the spot lights

here is why I can drive at night from mildura to Broken hill on high beam most of the way 4 or 5 hour s very little or no traffic I have seen a car on the side of the road 3 hours out of mildura the fuses kept burning out not wired up properly to much heat.

now just look at it this way it is a form of insurance to get auto electrician to do the job you will have peace of mind knowing it was done correct

if your car is insured and you have a fire you can make a claim if you do the job your self you will more than likley not be insured

most important is the safety of your passengers it is your responsibility to get them from point a to b safely

you may save money by doing it your self but in the long run you may be paying a higher price

simple choice
AnswerID: 518900

Reply By: grunta1970 - Sunday, Sep 29, 2013 at 16:43

Sunday, Sep 29, 2013 at 16:43
Hello all. Thanks is for all the replies. With most things I tend to be a 'have a go' type and not rely on the experts straight away. As much as I don't know a lot about this sort of stuff at the moment, I am prepared to ask the questions (sometimes stupid) to get me to the point where I'm confident enough to do it myself. At the moment I'm not at that point so I'm not going to jump straight into it.

AnswerID: 518903

Follow Up By: Batt's - Sunday, Sep 29, 2013 at 18:18

Sunday, Sep 29, 2013 at 18:18
If you lived in mackay I could help you wire them up legally.
FollowupID: 798856

Reply By: Member - Stuart P (WA) - Monday, Sep 30, 2013 at 18:13

Monday, Sep 30, 2013 at 18:13
you will need 3mm twin core
1 x relay
1 x switch
4mm twin
1 x fuse holder
connect one end of the 3mm twin to either side of the headlight plug(the vertical pins)
mount your relay close to the battery , loop the 3mm so there is enough wiring to make a neat connection across pins 85 and 86 of the relay, split the 3mm twin sheathing, cut the red wire crimp each cut end, place the crimped ends on pins 86 and 85.run the rest of the 3mm twin into the cab to the switch crimp the ends of the wire, join to the switch.

connect the red of the 4mm twin to terminals 87 on the relay, connect the black wires of the 4mm twin to earth.run the wires to the spotlights.

connect the fuse holder to pin 30 on the relay.
connect the other end of the fuse holder to battery positive, put in 25-30 amp fuse to suit

this system will work on most vehicle applications . except vw, and commodore

AnswerID: 518963

Follow Up By: Batt's - Monday, Sep 30, 2013 at 21:29

Monday, Sep 30, 2013 at 21:29
Stuart P maybe you had better check the amps for the wire you use you will need minimum twin core 5mm it can handle 27amps 4mm is for 15amps you would be overheating the wire and it would eventually fail 2 x 100w lights will draw 16.6amps. If the lights are 100watts each a 20amp fuse will be fine it will give you just over 3.3 amps left if that blows there is something wrong. The 12 Volt Shop has a chart with cable size and amp ratings in the twin core wire section it's very handy. When I worked at TJM we used twin core 6mm if the customer got bigger lights later on all they had to do was change the fuse.
FollowupID: 798931

Reply By: Member - Stuart P (WA) - Tuesday, Oct 01, 2013 at 23:12

Tuesday, Oct 01, 2013 at 23:12
As an auto electrician for the last 30 years I would argue that the distance travelled from the rlay to spots in this instance 4mm twin is adequate, else the thousands of spot hook ups I have done would cause the fire depts australia wide in constant employ.I have suggested a20 -30 amp fuse which is more than capable to cover 2/3over current,
AnswerID: 519043

Reply By: Member - Stuart P (WA) - Tuesday, Oct 01, 2013 at 23:44

Tuesday, Oct 01, 2013 at 23:44
, most of the relays i have used , bosch , narva , hella , have all had 2 87 terminals each had the capacity of 15 amps each, for a combined of 30 amps at 12v, ask yourself the operating voltage of a vehicle . it is not 12 v. whilst running is 13.8 v - 14.2v this brings the amps down to +- 6.75 amps. amps 1/2 with increased voltage
AnswerID: 519044

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