foster461 Posted March 23, 2015 Report Share Posted March 23, 2015 Here's what I'm thinking for how to wire up the fog and spot lamps. This will have three wires running down the RHS of the engine bay, one heavy gauge wire that will power either or both lamps and the two narrower gauge wires between the switches and the relays. The relays and the rest of the wiring are all up front under the apron. The two relays can be mounted on the RHS inner fender under the apron. I'm assuming perhaps wrongly that there will be some protection from the weather up there, say behind the headlamp bucket. Anyone see anything wrong with this ? Quote Link to post Share on other sites
RobH Posted March 23, 2015 Report Share Posted March 23, 2015 Yes that location for the relays is fine - I have done a similar thing with relays for the headlamps which works well and makes the lights brighter, as well as extending the life of the dipswitch contacts. The scheme looks fine. I guess parking lamp = sidelight this side of the pond (!) Rob Quote Link to post Share on other sites
foster461 Posted March 24, 2015 Author Report Share Posted March 24, 2015 Yes that location for the relays is fine - I have done a similar thing with relays for the headlamps which works well and makes the lights brighter, as well as extending the life of the dipswitch contacts. The scheme looks fine. I guess parking lamp = sidelight this side of the pond (!) Rob Being bi-lingual I get discombobulated sometimes. Were side lamps never called parking lights in the UK, even back in the 50's ? Quote Link to post Share on other sites
BrianC Posted March 24, 2015 Report Share Posted March 24, 2015 (edited) Being bi-lingual I get discombobulated sometimes. Were side lamps never called parking lights in the UK, even back in the 50's ? Yes they were (at least where I lived in Dover). BTW - Do the wires from relay to lamps really need to be heavy gauge? I am planning to do the same with headlamps and fog/driving lamps but hoped to be able to use blue/red and blue/white wires from existing (recently new) loom for headlamps. Edited March 24, 2015 by BrianC Quote Link to post Share on other sites
ianc Posted March 24, 2015 Report Share Posted March 24, 2015 Depending what bulbs/sealed units you have, each headlamp or spotlamp is likely to be rated at 55-70 watts, which means a maximum of 6 amps. Choose the cable accordingly - if it was good enough for the original headlamp unit, it will suffice for this. But don't daisy-chain the wiring, which would mean that part of it could be carrying twice the current - not good! Ian Cornish Quote Link to post Share on other sites
stuart Posted March 24, 2015 Report Share Posted March 24, 2015 When fitting relays you are essentially taking the load off the switch as that is the weaker point on this sort of system so yes the original wire to the headlamps as long as its in good condition (and Im not talking original cloth covered early TR2 to BPF bulb here!) would be sufficient providing you arent going silly and using 100W bulbs! Stuart. Quote Link to post Share on other sites
foster461 Posted March 24, 2015 Author Report Share Posted March 24, 2015 I dont know what wattage the fog and spot bulbs are yet. I ordered the repro fog and spots from Moss ( 5 inch diameter, stem mount). Once I get them I'll see what kind of current I need to plan for. Re the parking vs side lamps, I have pdf copies of most of the TR3 manuals and they all refer to parking lights, I assumed that is what they were intended for back in the day when you parked in the street. Stan Quote Link to post Share on other sites
stuart Posted March 24, 2015 Report Share Posted March 24, 2015 The spots are normally 55W I think. Stuart. Quote Link to post Share on other sites
Eddie Cairns Posted March 24, 2015 Report Share Posted March 24, 2015 (edited) As the car is not modern you do not need a tell tail light on the fog lamp switch but the fog lamp must only be used in bad weather. The wiring is fine. The spot lamp is an auxilary main beam headlamp as it is not a fog lamp. That's the law, 1989 lighting regulations. It must go off when the main beam is off. Therefore you cannot run the low ampage switching from the side lamp wiring. It must feed from the main beam headlamp wire. If there are two fog lamps they must be within 400mm from the side of the car. If only one is fitted no need to worry about that. I would use relays with their own fitted fuse eddie Edited March 24, 2015 by Eddie Cairns Quote Link to post Share on other sites
foster461 Posted March 25, 2015 Author Report Share Posted March 25, 2015 As the car is not modern you do not need a tell tail light on the fog lamp switch but the fog lamp must only be used in bad weather. The wiring is fine. The spot lamp is an auxilary main beam headlamp as it is not a fog lamp. That's the law, 1989 lighting regulations. It must go off when the main beam is off. Therefore you cannot run the low ampage switching from the side lamp wiring. It must feed from the main beam headlamp wire. If there are two fog lamps they must be within 400mm from the side of the car. If only one is fitted no need to worry about that. I would use relays with their own fitted fuse eddie Good point about the spot lamp Eddie, if I am only likely to use that when using the high beams I can hook the spot lamp relay into the high beam circuit just as easily. Stan Quote Link to post Share on other sites
Don H. Posted March 25, 2015 Report Share Posted March 25, 2015 ...That's the law... Where are you based, Eddie? Are you referring to US vehicle lighting regulations, which are a bit of a mish-mash of federal and state rules? Frankly, nobody cares that much about auxiliary wiring details on rarely-used vintage cars over here, and vehicles normally have to meet only the standards in place when they were made anyway. US FMVSS (Federal Motor Vehicle Safety Standards) and emissions regulations really got started in the late 1960s. When our sidescreen cars were built there really weren't that many rules, and the few lighting regulations back then mostly dated from SAE standards from the 1930s as far as I can tell. Quote Link to post Share on other sites
McMuttley Posted March 25, 2015 Report Share Posted March 25, 2015 A perfectly timed post Fossy. A couple on 'ancillary' (see what I did there!) questions. Do the red wires simply splice into the respective parking and main beam lamps at a convenient point? (Any recommended splicing techniques?) Is there any need for a fuse in the red wire between relay and splice? I have both fused and non-fused relays, does it matter? I am also installing a manually switched reverse lamp, are there any particular issues arising from the length of wire to the lamp, eg, relay in boot or under dash? Thanks Quote Link to post Share on other sites
stuart Posted March 25, 2015 Report Share Posted March 25, 2015 Where are you based, Eddie? Are you referring to US vehicle lighting regulations, which are a bit of a mish-mash of federal and state rules? Frankly, nobody cares that much about auxiliary wiring details on rarely-used vintage cars over here, and vehicles normally have to meet only the standards in place when they were made anyway. US FMVSS (Federal Motor Vehicle Safety Standards) and emissions regulations really got started in the late 1960s. When our sidescreen cars were built there really weren't that many rules, and the few lighting regulations back then mostly dated from SAE standards from the 1930s as far as I can tell. I think he is quoting UK regs by the sound of it. Stuart. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 25, 2015 Report Share Posted March 25, 2015 Go LED for the bulbs and you will dramatically drop the power consumption and need for fat wires. maybe even relays.... Peter W PS I have no idea what LED spot lamp bulbs are available but no doubt someone on here has researched them. Try Goffy the motor bike man http://www.norbsa02.freeuk.com/ Quote Link to post Share on other sites
foster461 Posted March 25, 2015 Author Report Share Posted March 25, 2015 I think he is quoting UK regs by the sound of it. Stuart. I'm not too concerned about lighting regs. As Don says at least here in MA there is little attention paid to these old cars as long as we pay the $35 a year for the inspection sticker, pay the excise tax and insure them. I would like to do what makes sense though, a bit like the OD logic controller on the TR6 to stop me from doing stupid things by accident. Stan Quote Link to post Share on other sites
foster461 Posted March 25, 2015 Author Report Share Posted March 25, 2015 A perfectly timed post Fossy. A couple on 'ancillary' (see what I did there!) questions. Do the red wires simply splice into the respective parking and main beam lamps at a convenient point? (Any recommended splicing techniques?) Is there any need for a fuse in the red wire between relay and splice? I have both fused and non-fused relays, does it matter? I am also installing a manually switched reverse lamp, are there any particular issues arising from the length of wire to the lamp, eg, relay in boot or under dash? Thanks Hi Austin, I'm not the best person here to be giving electrical advice but here is my best guess.. For the connections into the loom there are already bullet connectors up front for all of the front lighting. So I will just plug in where there is already a connector. If I need to I will swap out say a single bullet sleeve for a double to create an additional connection point. I always use original style sleeves and bullet connectors when I add anything and despite the many people that say the connectors should be crimped, I solder them. The red circuit is already fused on the USA cars which is why I chose it to power the relays. I'm not familiar with fused relays, I'll have to look that up !. For relays I like to use the Bosch style 4 or 5 pin relays and sockets. I use the sockets that accept the terminals with a tang so I can incorporate them into the wiring directly without having to join my wiring to the relay wiring. For the reversing lamp, that is not a high wattage lamp so I doubt that you will need a relay or very heavy gauge wiring. A fuse close to the power source is always a good idea to protect the wiring. Stan Quote Link to post Share on other sites
Don H. Posted March 25, 2015 Report Share Posted March 25, 2015 I think he is quoting UK regs by the sound of it. Stuart. Yup, that's what it sounded like. Perhaps Eddie didn't realize the op is in the USA. Quote Link to post Share on other sites
foster461 Posted March 25, 2015 Author Report Share Posted March 25, 2015 Yup, that's what it sounded like. Perhaps Eddie didn't realize the op is in the USA. It is an easy mistake. I live in Dunstable with friends nearby in Worcester, Gloucester and Chelmsford. We do not have an Ashby De La Zouch though, apparently no pilgrims came from there to form New England. Stan Quote Link to post Share on other sites
Eddie Cairns Posted March 28, 2015 Report Share Posted March 28, 2015 (edited) Sorry guys I am refering to the 1989 UK Lighting Regulations. The poster is from the US. To be honest even this was a UK car and it went in for it's MOT test if registered after 1960. It is unlikey that the MOT tester would even check the operation of these lights as I assume they would be assumed as period pieces rather than part of the lighting system on an older classic car. eddie Edited March 28, 2015 by Eddie Cairns Quote Link to post Share on other sites
stuart Posted March 28, 2015 Report Share Posted March 28, 2015 Sorry guys I am refering to the 1989 UK Lighting Regulations. The poster is from the US. To be honest even this was a UK car and it went in for it's MOT test if registered after 1960. It is unlikey that the MOT tester would even check the operation of these lights as I assume they would be assumed as period pieces rather than part of the lighting system on an older classic car. eddie If fitted they have to work correctly at the time of testing, so yes they would test the operation of them over here. Stuart. Quote Link to post Share on other sites
foster461 Posted March 29, 2015 Author Report Share Posted March 29, 2015 The Moss fog and sport lamps were delivered during this week and they are both fitted with 48w bulbs. So if I want to just bring one power lead from the battery to the front we have 96W total if both lamps were to be on at the same time. This would be unusual but not impossible unless I take steps to prevent it. 96/12 = 8 amps total load for the power feed from battery to relay. For each individual lamp we have 4 amps So based on the short distances I'm thinking of this for the cable size: Use 14 gauge for the single power lead from battery to relays Use 16 gauge from relays to the lamps Use 18 gauge to power the relays via the switches My wiring sleeve from firewall to relays will need to accommodate one 14 gauge wire and two 18 gauge wires. Sound good ? Stan Quote Link to post Share on other sites
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