Side lights, indicator replacement

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Molly123
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Side lights, indicator replacement

Post by Molly123 »

Hi
I’m replacing the side light flasher units to the front of my car. I’ve wired green to green and red to red, but the side light comes on and also flashes. The orange does not come on at all. Help please.
Seth
ManyMinors
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Re: Side lights, indicator replacement

Post by ManyMinors »

You haven't got the light earthed properly. That is what is causing the trouble. You need to clean up the fixings so that the light is earthed to the bodywork or run an earth wire to the light.
Molly123
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Re: Side lights, indicator replacement

Post by Molly123 »

Hi ManyMinors
The fittings are new. I’m completely lost with electrics. How do i earth the lights?
Seth
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geoberni
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Re: Side lights, indicator replacement

Post by geoberni »

Just to confirm you've got post 1963 combined unit?
i.e. these https://www.morrisminor.org.uk/userfile ... P170_3.jpg

Are they direct replacements or are you changing anything such as from separate lights fittings on an older car?
Are they actually fully fitted to the car or are you just trying it out with it hanging on the wires?
Were the originals working before you changed them?
(You'd be surprised how many people don't start from a 'known state' when doing this sort of thing)

Once fitted to the car the earth return is through the housing and the mounting bolts/screws.
Basil the 1955 series II

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Molly123
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Re: Side lights, indicator replacement

Post by Molly123 »

Thanks geoberni
They are direct replacements. I’m trying them out dangling from the wires. The originals were working fine, but no earth wire to the unit.
Seth
ManyMinors
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Re: Side lights, indicator replacement

Post by ManyMinors »

I don't know how else to explain it really. A light can only work if there is a live supply and an earth. From your description you have no earth, so when you switch on the light and the current runs down one of the supply wires to the bulb, it tries to earth itself back up the only available path which is your other supply wire. The red wire is the sidelamp and the green is the flasher. For the light to behave in the way you describe, it plainly has no earth which is achieved by creating a clean metal contact between the new light and the body of the car. Hence my suggestion that you clean up the fixings - the mounting screws and surrounding bodywork. Have you done that yet? People who fit glassfibre wings always suffer from this trouble because electricity cannot flow through glassfibre to an earth. Neither can it through rust, or paint or body filler. That is why you need to ensure that everything is clean. Failing that, you need to attach a new length of wire cable to the new light and then attach the other end to a clean metal earth point on the car.
ManyMinors
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Re: Side lights, indicator replacement

Post by ManyMinors »

Our posts crossed paths. You need to attach the light to the car in order to get an earth :wink:
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geoberni
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Re: Side lights, indicator replacement

Post by geoberni »

Molly123 wrote: Thu May 07, 2020 10:22 am Hi
I’m replacing the side light flasher units to the front of my car. I’ve wired green to green and red to red, but the side light comes on and also flashes. The orange does not come on at all. Help please.
Seth
I was initially confused by the Indicator not doing anything since it's earth returning through the other circuit, but as it's a 5W side light and a 21W Indicator, their respective resistance values will be a factor. The eventual Earth path will be going via at least one other lamp also, so that's a factor. :roll:

Earth problems can cause some really weird stuff to occur as electricity will always find a path home if at all possible. I used to hate it when we found Earth problems on an aircraft when I was in the RAF...
Basil the 1955 series II

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Myrtles Man
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Re: Side lights, indicator replacement

Post by Myrtles Man »

geoberni wrote: Thu May 07, 2020 12:59 pm
Molly123 wrote: Thu May 07, 2020 10:22 am I used to hate it when we found Earth problems on an aircraft when I was in the RAF...
The inability to get it to take off? :lol:
Molly123
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Re: Side lights, indicator replacement

Post by Molly123 »

Thanks all. Got it working😁😁
Can I now earth the
second light from the first?
Seth
ManyMinors
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Re: Side lights, indicator replacement

Post by ManyMinors »

As long as the light as a unit is earthed, each light within it should work. You only need one earth for them both to function.
Molly123
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Re: Side lights, indicator replacement

Post by Molly123 »

Thanks. MM
Seth
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geoberni
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Re: Side lights, indicator replacement

Post by geoberni »

Myrtles Man wrote: Thu May 07, 2020 1:11 pm
geoberni wrote: Thu May 07, 2020 12:59 pm
Molly123 wrote: Thu May 07, 2020 10:22 am I used to hate it when we found Earth problems on an aircraft when I was in the RAF...
The inability to get it to take off? :lol:
:lol: :lol:
I once (late 70s) traced a fault on a Harrier back to the main Earths at the rear of the batteries; there had been an unnoticed/unreported battery spillage, and the acid had caused corrosion around the Earth Bolts. Took a couple of days to clean up and neutralise the acid, and replace some damaged Rig Crimps with a month of daily monitoring using litmus paper to check it had all been removed.... :roll:
Basil the 1955 series II

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