|
|
Aug 16, 2017 19:45:42 GMT
|
I'm pasting this text from a question already posted on the Scimitar Facebook page. So there may not be enough info in here for non Scimitar people regarding the lights and wiring but it's a start and if anyone thinks they might be able to help and needs more info please ask and I will do my best to supply it... although I'm not very knowledgeable about electrics....
Electrics question. Rear lights, Scimitar SE5a 1973.
Hi there, electrics is really not my strong point. I am making a lot of good progress with converting my rear light clusters from the standard Lucas rectangle units to three 'classic' round bullet lights. I have a problem that I can't fix however, and I'm wondering if there is a simple thing I'm overlooking. On the Lucas lights, behind the coloured lenses, there are three separate lamp units. The red one is dual-purpose: rear lights when the headlights are on, and also brake lights. The rear lights are the weaker filament and don't shine so brightly. The braking filament is the brighter of the two.
On the Lucas unit there are only two connectors... one for the live, and one for the neutral (I assume that's what they are as one wire is red/black and one is green on my car). The red/black wire is two wires bonded side by side. But both those twin red/blacks are wired together into the same connector for the Lucas unit. The green is a single wire. So I have repeated all of that with my new lamp fittings. The twin red/black wires have been stripped of insulator at the tips and wound together inside a new spade connector terminal, and the green is wired to connect to the second terminal on the new unit. But what I'm getting is that when I put my headlights on, the brakelight filament is burning brightly as the rear lights, and when I press the brake, the smaller, weaker filament is activated, and so my brake light is very dim. When I have my lights on you can't even see the brake light activating as the rear light is shining so brightly.
Does anyone out there have any idea what I may have done wrong? I've carefully replaced everything like for like. I am currently thinking I might need a split connector so the two red/blacks can be connected separately to each other although I can't honestly see how that would make a difference as it wasn't like that on the Lucas unit. Any thoughts, ideas or further questions (about the wiring or functionality) most welcome.
|
|
Last Edit: Aug 16, 2017 19:46:51 GMT by Deleted
|
|
|
|
|
Aug 16, 2017 19:54:12 GMT
|
I am assuming they are tbe landrover type?
If so one wire is brake lights one side lights and the earth through the mounting screws, sounds like your earth is missing?
The strange behaviour is because it s now earthing through the second bulb.
|
|
|
|
|
|
Aug 16, 2017 20:12:21 GMT
|
I've actually created a daisy chain of earths across each lamp fitting, and all are (now) screwed in and working well and earthed to the rear frame of the car. So I don't think it's a lack of earth causing me any problems (that was the previous problem I tackled when I first put them all together a couple of days ago and discovered that the lights were generally weak across all bulbs). But it seems from the Scimitar FB page (just now) that I may have somehow mis-labelled the two red wires and put the side light wire on the Brake and the brake-light wires on the sidelight terminal. What really confuses me is that I thought wire colours indicated something... so I can't figure out why (a) there are two red/blacks bonded side by side as one connector, and then a green wire for the other connector. The only way I could figure it is that one of the twin red/blacks must be on some kind of relay that makes one circuit for the rear lights (coming back out through the single green wire) and the other twin red/black is for the brakes and similarly makes a connection that routes through the green. So as a stage 1 in the morning, I'm just going to swap the red/black twin wire and the green wire over onto each others terminals, and maybe my car won't blow up, and the lights will work. If not though, I think I'm going to have to think about pursuing some kind of split 'T' shaped connector to create two distinct connections to the same terminal for each of the red/blacks... my theory being that maybe I've crossed them over far more than they were originally when I fixed them into their new spade connector. Landrover type... not sure. They are 3rd party copies of the old Lucas bullets. I looked closely at a Land Rover today and they were a different shape/size. Possibly more like original Mini lights. They are made/packaged by a company called Grayston. The red is GE83 "red stop/tail" 12v. 21.5w bulb.
|
|
Last Edit: Aug 16, 2017 20:13:25 GMT by Deleted
|
|
ChrisT
Club Retro Rides Member
Posts: 1,635
Club RR Member Number: 225
|
|
Aug 16, 2017 21:21:56 GMT
|
Obviously something's wired the wrong way round but I'm struggling to picture what you've done from the description - a photo would help no end.......
I would have thought it's as simple as the red and black wires were tail and stop (or stop and tail) +ve input and green is ground.
|
|
|
|
fad
Posted a lot
Posts: 1,781
|
|
|
Photos will help. But in short you have your tail and brake lights reversed.
Pop a pic up with labels asap and will show you what to change.
|
|
|
|
|
|
|
At this point a pic would be of little help as the wires in question are buried in the side of long dark cavities at the back of the car and buried in a mass of loom wiring. It can only be one of two things 1. The green is not a ground but is in fact the rear light supply. The twin red/black wire (both wires in the twin are stripes of red/black, there isn't one red wire and one black) are the brake light. I have simply got each on the wrong terminal. or 2. The way the twin red/blacks were wired into the original connector kept them separate somehow creating a clean division of circuitry despite using the same spade connector. One wires supplies electricity to the smaller filament, and one to the larger filament (with some kind of relay thing choosing which wire to connect) By twisting their cores into a single element that is gripped in the new spade connector, I have somehow muddied the clean circuitry of two different circuits. Number 2 seems more logical because it explains why there are two wires to one single connector... and yet less likely to be the culprit because I don't see how that would result in a perfect swap of features. In the absence of a useful photograph, here is a home made wiring diagram... I guess my main point of confusion is why there are twin red/blacks going in if they're not doing completely different things. But my grasp of electrics breaks down at that point as they are both going to the same place and therefore there is no way for the lamp unit itself to distinguish which filament to light up... the power is going to a single terminal/connector on the lamp unit.
|
|
Last Edit: Aug 17, 2017 8:16:28 GMT by Deleted
|
|
fad
Posted a lot
Posts: 1,781
|
|
|
Right. let's just clarify stuff.
You don't have live and neutral, you only have lives. Light fittings earth through the chassis, or sometimes have a pigtail off the surround to connect to earth.
You have red and black joined together, and green alone. The reason you have wires together, is that they are daisy chained off (so you have a live in and out on the same spade).
You almost certainly have the two on the wrong connectors. Swap them over and enojy your correct lights. Let me know if this does not cure it and i will look in more depth for you and talk you through it.
|
|
|
|
|
|
|
Looking at the wiring diagram on my Firenza (similar seventies, standard-ish wiring colours) the stop/tail lamp has two wires, one is red, the other green. The red is the rear light power, which daisy-chains from offside, to the number plate light, to nearside. The green is the stop light, which daisy chains from offside to nearside. So on the offside I have two of each wire colour, with the second going out to the other side of the car. On the nearside, I only have one of each wire.
Obviously on mine it earths directly into the body through the mounting screws, so I'd expect you would have another wire to earth the lamp body. If you look inside the stop-tail lamp housing with the bulb removed, you should be able to see that in the bottom of the hole for the bulb, there are two connections. One is for each filament, and the earth is around the vertical edge of the hole.
ETA, as fad said above.
|
|
|
|
|
|
|
Cheers fellas. I'm ITCHING to get back out to my car to do the very simple thing of switching these wires over... but it's raining, which means my wife has changed her plans and instead of me having all morning to fiddle and hopefully finish this job finally, she's left me in charge of the kids and gone off on her own.
So frustrating. I sometimes think wives are hard wired to over-ride car fiddling opportunities.
= )
I'll report back when I finally get a moment.
|
|
|
|
|
|
Aug 17, 2017 10:46:12 GMT
|
Just ran outside the moment my wife walked back in.
Problem solved. It was option 2 as you said Fad... the wires were on the wrong terminals. Cheers for your thoughts and help fellas.
Now I just need to find the time to pull the RH assembly and do proper earths on that, and then I can finally think about finishing this off properly.
I do wish half day jobs only actually took half a day as opposed to being three days in total, spread out in frantic spurts of activity against the clock over a two month period.
|
|
|
|