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Need step by step to wiring spotlights

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Sorry, I feel like an on-going idiot. I have searched but not found the word of one syllable answers I need. I have downloaded a circuit diagram for spotlights from here by Landymanluke and whilst I can follow the logic I need help with a few questions since never done the likes of this before.

First of all where do I physically attach the relay to the bodywork? In the engine compartment, near the battery, near the lights or near the switch???

Second, do I pick up the red +ve supply from an existing fuse or am I better trying to put in a new fuse and separate feed (sorry I haven't looked yet to see if there are any spare slots) If an existing one, which one is best to use? I suppose ditto, do I run the black earth cable back to the battery too? ANd if so how do I best attach it to the battery cable?

The over-ride switch, now. Do I need any special rating (a rocker with warning light looks as if it would be helpful). ALso where do I best pick up the mainbeam feed to go to terminals 85 and 86 on the relay?

I presume the line thickness on the diagram indicates the weight of wire needed. If so, then the red and the black would be 25 amp? And the blue 16.5 amp - does that sound right?

Sorry for so many questions but it really seems difficult for me to visualise. Have ordered crimping kit and pre-insulated terminals so hopefully they will help in the process!

Also having physically attached the lamps to the bar is it usual to do something to protect the nut? It seems as if it would be all to easy simply to get a spanner and remove them - or am I getting paranoid!

So many questions but that is why I feel so nervous about it.

I have now successfully got the A-Bar in place and am now keen to get the lights in too.

Thanks in anticipation

Best wishes

Malcy

post-3029-1183148071_thumb.jpg

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The relay can be bolted to the wing top inner edge. 

ignition controlled power supply can be found in the engine bay, look for a White with Orange tracer, [air condition feed] this will supply the relays needs, fit a in-line fuse holder.

earth can be attached to the earth point on the bulkhead [should be adajacent to the brake servo]

to get the lights to work with main beam, just connect into the appropriate wire behind the headlights the wires run along the inner wing to the bulkhead multiplugs.

switch needs to handle a minimum of 10amps, a good rocker switch with warning light can be sourced from www.vehicle-wiring-products.co.uk

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I'd earth back to the battery, it's worth saving the potential hassle.

the override switch need only be rated for the load placed on it by the relay coil - typically well less than an amp, a few hundred mA. In short, you will struggle to find an automotive style switch that isn't suitable.

Red and black wires need to be rated to AT LEAST the rating of the bulbs, more to allow a safety margin is recommended.

The blue wire, like the switch, takes very little current, again you will probably struggle to find an automotive wire that isn't big enough.

I would add a new fuse, mainly to keep things simple, but the choice is yours. having the fuse nearer the battery is a good thing.

Any other questions, just ask.

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1st picture -- Earth point on bulkhead inboard of where the multiplug looms go inside to instruments/dash area.

2nd picture -- relay located between brake master cylinder & radiator header tank.

3rd picture -- closer view of relay.

hth :D

post-20-1183149820_thumb.jpg

post-20-1183149897_thumb.jpg

post-20-1183149936_thumb.jpg

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just been outside and taken those Ralph? if so, that's dedication to the cause!

Yep, took those while you were adding your reply :i-m_so_happy: Having a 110 outside & a digi camera is really handy sometimes.

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Thanks guys for such helpful posts - especially the photos which really do help.

I am beginning to get a much clearer picture. Who knows when I am 105 years old I may understand!!

I will now begin to gather kit and also explore where I can find the wires. It is odd, I am quite happy wiring computers but find the scale of the 90 a bit more than I am used to!

Hopefully that will solve things but if not hope it is OK to come back

Best wishes

Malcy

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Red and black wires need to be rated to AT LEAST the rating of the bulbs, more to allow a safety margin is recommended.

So if it is two 55w lamps (I will need to check bulb but I think they are 55w) that gives me 110w

Watts = Amps x Volts (from my O level days) so 110w and 12v means about 10 amps going down the red and black wires - which means 16.5 amp should be fine but 25 amp would be better and is only 10p/m dearer.

Have I got that right?

Malcy

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So would using 25 amp wire and a 20 amp fuse be about right - gives 100% over anticipated 10 amp draw or is that too much? If so, then presumably 15 amp fuse?

Sorry for such elementary questions but I have no feel for what tolerance should be allowed.

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110W at 12V = 9.2A

110W at 14V = 7.9A ...your alternator will produce 14.4V

In theory, a 10A fuse will be fine, until your battery voltage gets to 11V.

In practise, a 15A fuse is suitable if the 10A regularly blows, a 20A fuse is too high.

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So would using 25 amp wire and a 20 amp fuse be about right - gives 100% over anticipated 10 amp draw or is that too much? If so, then presumably 15 amp fuse?

Sorry for such elementary questions but I have no feel for what tolerance should be allowed.

15amp fuse as I've used [the blue plastic thing] go for the blade type fuses as their more common now & easier to wire into a circuit. the bulbs are H3 halogen at 55watts each :D

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To protect your lamps from being removed quickly/quietly.

Try looking on Screwfix's website for stainless shear nuts IIRC M8/10/12, assemble with loctite.

The torque shearing values are sufficient to hold the lamps without them moving.

Rod

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Hi guys. Got the crimping kit and then went on holiday so now back and started the job.

I have got the relay fitted as per Ralph's picture 2 and also the relay plug 86 wired back to the earth point in Ralph's picture 1. I have also got the two lights fitted to the A-bar and have wired the two black earth leads from the lights together using a bullet at one end and a piggy-back connector at the other end - so I can then run a common earth from the piggy-back to the earthing point.

My first question is when you say earth back to the battery do you mean run the new earth wire for the spotlights alongside the main earth wire to the battery box and then fit a ring connector onto the battery clamp that attaches the earth cable to the battery post?

I think I would be better using a double bullet connector for the live feed to the two lights rather than the piggy-back since there seems to be a bit too much bare metal around with the piggy-back for my liking - OK for earth but not for live. And, of course, there isn't a double bullet connector in the kit I got so will have to put in another order!

I still need to dig around and find the ignition feed to take my red cable from and also the blue mainbeam cable for the switch feed so I am afraid I will probably come back for more questions.

Best wishes

Malcy

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my driving lights & front fogs are earthed at the mounting point or in the engine bay on any convienient bolt, never had any problems doing it that way.

you can get double common feed bullet connectors from either Halfords/local car shop or V.W.P

pick up the main beam feed from behind the right headlight & look for a white/orange trace wire at the bulkhead -- this is the ignition controlled feed for the air condition system [when fitted] or go behind the instrument pack & piggyback of the white wires at the ignition switch.

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Thanks Ralph, that is really helpful. Seems easier to earth back into the engine compartment.

I will order from VWP since I ordered a length of blue 25 amp cable when I meant to order red and it is probably best to keep it as colour coded as possible.

Have found the blue/white feed at the RH headlamp so just have to find the white/orange one.

Fingers crossed!

Best wishes

Malcy

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your a busy boy, if you can't find the white/orange -- go for the white at the ignition switch, just pull the instrument pack towards the steering wheel & disconnect the speedo cable for access :D

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Sorry, I feel like an on-going idiot. I have searched but not found the word of one syllable answers I need. I have downloaded a circuit diagram for spotlights from here by Landymanluke and whilst I can follow the logic I need help with a few questions since never done the likes of this before.

First of all where do I physically attach the relay to the bodywork? In the engine compartment, near the battery, near the lights or near the switch???

Second, do I pick up the red +ve supply from an existing fuse or am I better trying to put in a new fuse and separate feed (sorry I haven't looked yet to see if there are any spare slots) If an existing one, which one is best to use? I suppose ditto, do I run the black earth cable back to the battery too? ANd if so how do I best attach it to the battery cable?

The over-ride switch, now. Do I need any special rating (a rocker with warning light looks as if it would be helpful). ALso where do I best pick up the mainbeam feed to go to terminals 85 and 86 on the relay?

I presume the line thickness on the diagram indicates the weight of wire needed. If so, then the red and the black would be 25 amp? And the blue 16.5 amp - does that sound right?

Sorry for so many questions but it really seems difficult for me to visualise. Have ordered crimping kit and pre-insulated terminals so hopefully they will help in the process!

Also having physically attached the lamps to the bar is it usual to do something to protect the nut? It seems as if it would be all to easy simply to get a spanner and remove them - or am I getting paranoid!

So many questions but that is why I feel so nervous about it.

I have now successfully got the A-Bar in place and am now keen to get the lights in too.

Thanks in anticipation

Best wishes

Malcy

Just picking up from this thread .......... 2 questions if you would tolerate please

a) To confirm as per the diagram ...... the relay pin 86 connects to earth ?

B) Would it be a sin to run a wire from the starter +ve to pin 30 on the relay ? (15 A fused)

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Would a reply from me be acceptable? :unsure::)

85 or 86 doesn't really matter - earth to one and 12 v to the other. Both are connected to the relay winding to make it pull the contacts when activated.

I always use the battery cable connection on the starter for the 30 on relays. IMHO it's cleaner than the battery post that can be corroded from battery acid and vapours.

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