colin lad Posted August 17, 2014 Report Share Posted August 17, 2014 not sure this is the correct place for this kind of thread but it's going on 4x4 so put it here, here go's my problem. i have purchased a spot lamp to put on 4x4 it's going down low on my bull bar and will be aimed about 10ft in front of car for driving while out lamping,want a switch inside i can flick off when i have spotted my target, now the lamp has 2 wires coming out of back of it ,when i attach one to the positive terminal of car battery the light comes on without 2nd lead being connected if i try other lead on it's own it sparks so that obviously don't go there, now what i have done as a temp measure is to run a lead from the wire that makes light come on into car and connect it to a switch then another lead from other connector on switch back towards battery with a fuse in then connected it to positive terminal so light now works with switch, but what i would like to know is A, will this be ok as it is or B, do i need to connect other lead to anything as it has just been blanked off for the moment ?? hope that made sense colin or C just stick to being a butcher and forget electrics Quote Link to comment Share on other sites More sharing options...
wymberley Posted August 17, 2014 Report Share Posted August 17, 2014 You've said twice that it's going on - can we assume it's actually already on? The negative side is running back to the battery via the chassis and the earth strap. No doubt a sparky will give you the preferred option. Quote Link to comment Share on other sites More sharing options...
colin lad Posted August 17, 2014 Author Report Share Posted August 17, 2014 You've said twice that it's going on - can we assume it's actually already on? The negative side is running back to the battery via the chassis and the earth strap. No doubt a sparky will give you the preferred option. yeah sorry i put it on this morning into position was just not sure about leaving the other wire un connected colin Quote Link to comment Share on other sites More sharing options...
FoxyChris Posted August 17, 2014 Report Share Posted August 17, 2014 It's a bit odd. The second wire is the negative that should just ground to the chassis or back to the negative terminal on the battery. The fact the light works without this being connected means its grounding via the casing or something else. Is this a new light or second hand? Sounds like a fault has developed inside the light. Is the casing for it metal as well? Quote Link to comment Share on other sites More sharing options...
colin lad Posted August 17, 2014 Author Report Share Posted August 17, 2014 (edited) It's a bit odd. The second wire is the negative that should just ground to the chassis or back to the negative terminal on the battery. The fact the light works without this being connected means its grounding via the casing or something else. Is this a new light or second hand? Sounds like a fault has developed inside the light. Is the casing for it metal as well? yes the casing is metal and i drilled 2 shall hole in my bull bar and screwed it to that if the other wire just needs to go to earth i can drill and screw that too, though if the case is earthing then will that do? colin and it is new Edited August 17, 2014 by colin lad Quote Link to comment Share on other sites More sharing options...
daystate 177 Posted August 17, 2014 Report Share Posted August 17, 2014 The bull bar is acting as the earth in this case not uncommon on metal things best thing to do is make spare wire safe and tuck it out the way. Quote Link to comment Share on other sites More sharing options...
FoxyChris Posted August 17, 2014 Report Share Posted August 17, 2014 I agree in the sense that the bull bar is acting as the ground but it's not ideal. It may cause some issues if it gets wet. I'd ground the spare wire directly to the battery for peace of mind. Since it's on your bull bar anyway it won't take much work to route the wire to the engine bay and is the safer way to do it rather than letting it ground to exposed metal on the front of your vehicle. Quote Link to comment Share on other sites More sharing options...
colin lad Posted August 18, 2014 Author Report Share Posted August 18, 2014 thanks all spare wire now hooked up to negative colin Quote Link to comment Share on other sites More sharing options...
keg Posted August 18, 2014 Report Share Posted August 18, 2014 I would also run the light via a fuse and relay if you are going back to the battery. There are a few diagrams on here showing how to do it. Quote Link to comment Share on other sites More sharing options...
deershooter Posted August 18, 2014 Report Share Posted August 18, 2014 The power of the spotlight is probably more than the switch can take ,as said you need a 4 pin automotive realay of around 20 amp to be safe . The realay will have 2 pins for the coil these need to go to + through your switch and - the other two connectors one goes to the spotlight the other goes through a fuse and to the battery . Use good automotive cable of at least 1.5 mm Deershooter Quote Link to comment Share on other sites More sharing options...
longspoon Posted August 18, 2014 Report Share Posted August 18, 2014 I would suggest wiring via a relay as there is a possibility of the switch overheating....just a thought ! Quote Link to comment Share on other sites More sharing options...
keg Posted August 18, 2014 Report Share Posted August 18, 2014 Always wire via a relay and fuse. Quote Link to comment Share on other sites More sharing options...
colin lad Posted August 18, 2014 Author Report Share Posted August 18, 2014 have gone through fuse i will get a relay colin Quote Link to comment Share on other sites More sharing options...
Jaymo Posted August 19, 2014 Report Share Posted August 19, 2014 Halfords do an idiot proof pre wired relay kit Quote Link to comment Share on other sites More sharing options...
deershooter Posted August 19, 2014 Report Share Posted August 19, 2014 I agree in the sense that the bull bar is acting as the ground but it's not ideal. It may cause some issues if it gets wet. I'd ground the spare wire directly to the battery for peace of mind. Since it's on your bull bar anyway it won't take much work to route the wire to the engine bay and is the safer way to do it rather than letting it ground to exposed metal on the front of your vehicle. Every light and thing that uses 12 volts in your car uses the body of the car for the negative al most nothing has two wires going to the battery Body the other wire to the bull bar mounting Deershooter Quote Link to comment Share on other sites More sharing options...
Cannon Posted August 19, 2014 Report Share Posted August 19, 2014 What wattage is the light? Unless the vehicle is specifically wired negative earth I would earth the light to the chassis or bull bar in this instance. Some switches are designed to take high current flow, so you don't necessarily need to use a relay. They are preferred for safe wiring operations though. If the earth wire wasn't touching the chassis or bull bar when the light was lit, then there may be some dodgy wiring inside the light casing itself, with the light earthing through the casing and not the dedicated earth wire. Quote Link to comment Share on other sites More sharing options...
colin lad Posted August 19, 2014 Author Report Share Posted August 19, 2014 (edited) these are the lights i brought http://www.ebay.co.uk/itm/171375577483?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT only have one of them on bull bar on my Diahatsu sportrack it has 2 spotlights already on it but they are wired up to main lights and i just wanted the one small one pointing down on the ground for while out lamping colin Edited August 19, 2014 by colin lad Quote Link to comment Share on other sites More sharing options...
Cosd Posted August 19, 2014 Report Share Posted August 19, 2014 (edited) Hey Colin I would advise against using it at all before adding a relay. The current drawn from the spotlight will probably overheat the switch; if you're lucky the switch will burn out and you pop a fuse, worse case scenario is a fire!! I would take a positive wire direct from the battery, fused as close to the battery as possible. Take that positive to a switched relay. Earth the relay close to a bare metal point. Send a positive wire to the spot lights and earth the spotlights on bare neatly near the lights. You can get wiring diagrams for relays easily off the net. Use crimped spade and ring connectors on all your joints. More than happy to talk on the phone if you need any help. Forgot to add the switch is connected to relay as well. I would mount the relay close to the switch rather than the engine bay just to keep it out of the elements under the bonnet. Cos Edited August 19, 2014 by Cosd Quote Link to comment Share on other sites More sharing options...
longspoon Posted August 19, 2014 Report Share Posted August 19, 2014 (edited) Hey Colin I would advise against using it at all before adding a relay. The current drawn from the spotlight will probably overheat the switch; if you're lucky the switch will burn out and you pop a fuse, worse case scenario is a fire!! I would take a positive wire direct from the battery, fused as close to the battery as possible. Take that positive to a switched relay. Earth the relay close to a bare metal point. Send a positive wire to the spot lights and earth the spotlights on bare neatly near the lights. You can get wiring diagrams for relays easily off the net. Use crimped spade and ring connectors on all your joints. More than happy to talk on the phone if you need any help. Forgot to add the switch is connected to relay as well. I would mount the relay close to the switch rather than the engine bay just to keep it out of the elements under the bonnet. Cos +1 that's the way Edited August 19, 2014 by longspoon Quote Link to comment Share on other sites More sharing options...
colin lad Posted August 19, 2014 Author Report Share Posted August 19, 2014 Hey Colin I would advise against using it at all before adding a relay. The current drawn from the spotlight will probably overheat the switch; if you're lucky the switch will burn out and you pop a fuse, worse case scenario is a fire!! I would take a positive wire direct from the battery, fused as close to the battery as possible. Take that positive to a switched relay. Earth the relay close to a bare metal point. Send a positive wire to the spot lights and earth the spotlights on bare neatly near the lights. You can get wiring diagrams for relays easily off the net. Use crimped spade and ring connectors on all your joints. More than happy to talk on the phone if you need any help. Forgot to add the switch is connected to relay as well. I would mount the relay close to the switch rather than the engine bay just to keep it out of the elements under the bonnet. Cos thanks mate will give you a bell when the relay arrives colin Quote Link to comment Share on other sites More sharing options...
Cannon Posted August 19, 2014 Report Share Posted August 19, 2014 Have you ordered a relay yet Colin? If not I can send you one with fuses etc as well as a switch? Quote Link to comment Share on other sites More sharing options...
colin lad Posted August 19, 2014 Author Report Share Posted August 19, 2014 Have you ordered a relay yet Colin? If not I can send you one with fuses etc as well as a switch? yes this one http://www.ebay.co.uk/itm/291093491463?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT hope it will do colin Quote Link to comment Share on other sites More sharing options...
deershooter Posted August 19, 2014 Report Share Posted August 19, 2014 55 watts each total 110 wats Current = watts / volts 110/ 12 = 9.1666 amps constant current Too much without a relay The one you have ordered is fine Deershooter Quote Link to comment Share on other sites More sharing options...
will_gleave Posted August 20, 2014 Report Share Posted August 20, 2014 Wish id seen this earlier id have sent you one got loads of them. Quote Link to comment Share on other sites More sharing options...
little.bob Posted August 21, 2014 Report Share Posted August 21, 2014 yes this one http://www.ebay.co.uk/itm/291093491463?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT hope it will do colin hi mate you don't need all that fancy stuff my suggestion would be to tape a crow banger to live wire if it gets overloaded the wire will get hot the banger will go off and alert you and cut the power supply at the same time simples I have a couple if you want them cheers rob Quote Link to comment Share on other sites More sharing options...
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