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MG Midget and Sprite Technical - lights and spotlights

After looking at the cost to replace and have delivered to Ireland one of my headlight sealed units, I decided to convert them to the H4 Halogen type it an easy swap and to fit two spot lights. I live in rural Ireland so street lighting is as rare as rocking horse poo.

So even before I attempted the spot lights I noticed the dip beam was good but the main beam was very poor like candles.

The wiring harness was replaced about 5 years ago, the dash switch is faulty( needs tapping) and dip/main beam switch is showing signs of overheating these I have ordered replacements, I also noticed that the blue main beam warning light is on all the time, dip or high beam.

Its fair to say that my knowledge of auto electrics is poor. Would these two switches be causing to poor dip beam and permanent high beam warning light. the car is being restored so I am not sure if the main beam was the same with the old sealed units.

While waiting for the above parts to come I have fitted the spot lights using the attached wiring diagram but running the switch to the main instead of the low beam wire, but they are on all the time unless switched off at the switch, should they not just come on with the main beam.

any ideas

Rich

1973 midget



Rich65

Rich,
I too have very little idea about electrics but yours sounds like it might be wired up wrong which could lead to all sorts of problems.

Are you sure main and dip are not wired/connected the wrong way round somewhere?

If you have look at the wiring diagram in the Driver's Handbook (or Haynes or workshop manual) it will tell you the colour of the wires the lights and switches should be connected to.

Or if you email me I'll try to copy a colour A3 size Mk3 wiring diagram for you. My email adress is my first and surname at btinternet dot com (all lower case no spaces).

I'd suggest you disconnect your newly installed spot lamps for now to reduce the load as headlights aren't fused on Spridgets.

To get all the electric to your headlights your battery needs to be in good condition and well charged and all connections, switches, etc., from the battery posts to headlights, clean, secure and protected. For the other circuits this includes the fuse box and its connections eve the spring holders and fuses.



Nigel Atkins

Nigel,

The new loom was installed by my dad a few years ago so there may be a possibility of a wiring error, I am working off an original factory workshop manual that was sent out to the dealers the problem is it has all the midget models in it so 8 wiring diagrams, and my dad (78) can't remember which one he used and they don't say which one belongs to which model.

The wiring at the headlights seems to match the wiring at the switch blue/white main beam and blue/red dip
Battery is new but I'll give it a charge
The spot are disconnected now
Your wiring diagram would be great thanks

Rich
Rich65

It may be wired wrongly, but another possibility is the column stalk switch is on the way out. The contacts in the switch are very small and held on springy brass strips. As they age these become less springy and you can end up with the contact which alternates between high and low beam effectively contacting both at the same time. The switch could also be the reason for the dim light on dipped beam.

But, beware of replacement stalk units. They don't last as long as the originals (poor materials I think. In fact if the fault is with the switch it could well already be a replacement item.

The other thing always worth checking are the bullet connectors used in the wiring. These are prone to corrosion, especially on a car left standing for a while. Often the fault is easily cured with a bit of emery paper and there is no need to throw money at buying new parts!
GuyW

The wiring diagram given is ok in itself for the spots being powered via main beam (assuming you've connected green to main beam as you say). However, if the spots are on all the time (and the blue main beam indicator) then that suggests your dip switch is shorting as Guy alludes to I.e. it sounds like main beam is staying on when you think you're on dipped beam. Check the dip switch.
Bill
Bill Bretherton

Hi,


As you say the main beams are "like candles" I'd be checking the 3 way connectors on the sealed beams are wired correctly.


If your dad replaced the little looms out to the headlamp bowls he may have got it wrong!



If you're looking at the plug from the rear the earth (black) should be on the left, the dip beam (blue/red) in the top and the main beam (blue/white) on the right.



So many assume the earth goes in the top slot, I've seen loads of cars wired like this over the years. The dip beam works fine but the main is no good as it has no decent earth, May explain the permanent blue light as well!



Think about relaying the headlamp circuits to take the heavy loads out of the light switch and dip switch.



Good luck with this.



Regards Steve
Steve Smith Midget 1500

Not withstanding your other faults, swapping over (at the headlights) dip feed and the earth wire would give exactly the fault with your dip/main difference in brightness. You would get normal dip but very dim main and when on dip the blue light would be illuminated due to feedback from dip through the main bulb back to the blue indicator.

Rob

Beaten to it by Steve!!!!!
Rob aka MG Moneypit

I think you need to double check the headlight bulb connections; If you have the earth connection on the bulb swapped with the dipped beam filament bulb connection, it would cause main beam to be very dim (because the two filaments are in series) and it would cause the main beam warning light to stay on (because it would get it's supply through the Main beam filament when dipped)

See my attached work of art :)

EDIT: Beaten by both of you! I was too busy creating my work of art!


J Smith

Nice picture worth a 1000 words.

Must be the answer. All 3 of us can't be wrong?

Rob
Rob aka MG Moneypit

Hi guys,



Seen it done so many times, I bet we are!
Steve Smith Midget 1500

Ah, it wasn't clear from the OP that fault happened after rewiring so I now agree with above comments. I assumed correct connections had been made to headlamps as that would be the obvious thing to check........
Bill
Bill Bretherton

I agree with Steve that relays on the headlights is not a bad idea but it's not a priority for non-electricians like myself, and perhaps Rich, provided of course that the wiring and switches are in reasonable condition. I've not got relays and my headlights are bright and have worked fine for the last 9 years.

I suggest getting all that needs sorting on the car done first before going for improvements like relays, unless you have to replace the headlight wiring anyway.

The switches themselves, their contacts and connections and other connectors, such as bullets, as Guy pointed out can be easily taken apart and cleaned, without knowing about electrics.

Nigel Atkins

Gday Rich
to get the best light output you definitely need relays (sorry Nigel). Your wiring diagram is for the spot lights only. To get the best result and prolong the life of your switches fit relays to the low (dip) beam, High beam and the spots. Yes I know, three relays, but you need to be able to switch the spots independantly.
It is possible to repair the dip switch, new ones are an unknown quantity as reported. But whatever you use, new or old, fit fused relays.see pic. Replace all the dodgy bullet connectors, because once corrosion begins, no amount of cleaning will stop it returning.
HTH Cheers
Rod



R W Bowers

The new column stalk and dash switch have arrived from Moss, yes they do feel a bit lower quality. I will work through all your suggestions this weekend, thank you Nigel for the wiring diagram. Rod do you have a wiring diagram for fitting relays to the main/dip beam.

Thanks

Rich
Rich65

Hi Rod,
yes to get the very, very best you probably need relays but if all items are in good condition then you don't need relays to get very good headlighting. There's not that much difference between my H4 non-relay headligths, on dip and main beam, to my wife's 2008 modern car.
Cheers.
Nigel Atkins

Have to agree with Steve et al regarding the likely wiring anomaly.

Also, with due respect to Nigel, I concur that relays for Hi, Lo and Spot lights are a very good mod. I would call it essential myself. Mostly for the protection it gives the switchgear by minimising the current across the switches which were fine when new, but as you observed the modern replacements don't seem as good.
I suggest installing fuses as well, at least in the live feed to the relay secondary. Easy and cheap and if there's a problem you don't lose all your lights at the same time.

By the way Haynes isn't always completely accurate but it does contain excellent wiring diagrams for all models which makes it easy to find the right one for your car. Good luck.

Exit: crossed in the post Nigel. My lights are much better with the relays but I'm using original switches. No disrespect intended.
Greybeard

Sorry I meant to say fuses for each separate relay feed. You could go a step further by fusing all the consumers separately for a few pennies more, but I personally think that is overkill.
Greybeard

Rich,
for a start why not fit the new parts and see how you go. Fit one part at a time and test if you want to know which part was/is faulty or wired wrong, if you don't want to know then fit all the parts at once.

Whilst doing so do take the chance to clean and if required tighten (or replace) connectors and wires.

Whilst doing so check and clean battery posts and post clamps and brown wire connections on starter solenoid and of course all earth connections.

Only very recently I fitted a new column switch which I bought about three years ago (from an ebay supplier). I can't say I've noticed any real difference in brightness but there might be a very slight increase in brightness or I might be imagining it.

ETA - no problem with different views Greybeard, improvements are good but best after sorting the basics and not as support for items that should be replaced (not referring to your car).
Nigel Atkins

I'm not against relays although I see and find that the installation of relays and their wires often tends to be a bit awkward and untidy, the wiring on Spridgets tend to be a bit of a spiders web after decades of car use anyway.

The relay for my electric cooling fan is a bit of a mess of wires certainly not that neat in average real world fitting and use.

The (previous) electronic indicator flasher (relay?) unit fitted to my car - but I'm sure others could have made a better presentation.


Nigel Atkins

I found that the problem with the new reproduction stalk units wasn't that they didn't work well at first, but with how long they lasted. I had two new ones fail in under 4 years, whereas the original one on the car from new had lasted something like 35 years from new.

So a replacement will almost certainly work well when first fitted, but unless the supply of these has improved in recent years, it may well fail again within a fairly short space of time. When I fitted the 3rd replacement I also installed relays, but to protect the column stalk contacts, rather than to get brighter lights. It does seem to have cured the problem, 8 years on and counting!

As Nigel says, for normal use the lights are perfectly good without resorting to relays, but you do need clean contacts, connections and especially, good earths. And don't underestimate the gains from having good quality, and very clean, reflectors and headlight glass.
GuyW

Very good point about keeping reflectors and lenses, inside and out, clean on lights as it makes a big difference, as does cleaning the bulbs!

Headlights reflectors (on ours) can't be cleaned but if you're cleaning the reflectors on other lights don't use car polish as it'll take off the "silver", guess how I know, doh!

Also have clean reflective number plates, clean number plates are the law now??

When I can be bothered I've got some LED headlight bulbs to fit, I'm hoping this will reduce the strain on the new column stalk switch and help it last longer.

I already have LED indicator (and rear lights) bulbs so that reduces the strain a bit on those contacts and the (old) main light switch.

LEDs are legal on my year of car except for the front side lights which of course are not led bulbs even though you can get warm white LED versions.
Nigel Atkins

Hi,


It's not rocket science installing light relays and I'd say it makes a huge difference to the light output.



Here's a picx of the installation on my 1500. Dip, main and cooling fan mounted on the lh inner wing. Excuse the scruffiness, they've been there along time and the car is well used.



Regards Steve.


Steve Smith Midget 1500

Its not the relays that improve light output. Relays are just remotely operated electronic switches. What improves the light output is the new cables, new connectors and new earth points that get installed at the same time. But many people, me included, also install higher wattage bulbs at the same time, and these would excessively overload the little contacts in the stalk switches and are better used with relays.
GuyW

Relays do mean more wires (a lot more sometimes) and more connectors so potentially more scope for poorer performance if not installed well or when aged.

My H4 headlights I think are 60/55w and have been in for 6½ years on an old main light switch and a stalk switch that looked like it was was from another BL model and was on the car when I bought it. The stalk became loose about 4 or so years ago but always worked even after a cheque presentation at a local charity for kids with special needs where one little lad was waving it like a stick as he sat in the driver's seat. I felt sure he would finally break it and told the mother not to worry and let him enjoy himself as I'd got its replacement but had yet to install it. As it survived and still worked I left the stalk on even after that and only replaced it recently, a couple of years later.

When I removed it and unwound the wrapping tape I found the plug had its tails all soldiered to the wires on the stalk so my suspicions where right.

I now have, for the first time since owning the car, fully self-cancelling indicators - which is more than on my wife's modern car!

Like Guy's put I've no idea how long the new stalk will last but the LED headlights are a much lower load (I hope load is the correct electrical term, if not you know what I mean) so hopefully will help in the longevity.
Nigel Atkins

Hi Nigel,

I am very interested on your comments about the legality, or otherwise, of LED bulbs. Can you guide me to the relevant legal information please?

Cheers,

Ray
Ray Rowsell

Gday Rich
Sorry no diagrams I usually just use the force and 50 years of experience. See pic of relay install, the curved tube is the drive from the windscreen wiper. it was installed here because this is a convenient place to break into the main loom as it exits the firewall, and the battery is close. Relays are mounted on bases which clip together, the gadget on the left is a 40 amp circuit breaker. An upgrade would be to fit fused relays see previous post pic.
HTH
Chheers
Rod





R W Bowers

I agree Guy, When I rebuilt my Frog in 2010 I renewed the loom. It still had its original loom and apart from a PO adding an ammeter it was untouched. The difference the new wiring loom made was significant. All the lights were much brighter and worked more efficiently. I like Nigel do not have relays but still use the original 'glowing embers' headlamps although they still draw 55W on high (!) beam. The relay protects existing contacts which is why the starter motor is activated via a relay of some description.
Bob Beaumont

It would be interesting to compare voltage levels between battery, switch output and bulbs when on main beam to see where most loss is. On main beam there'll be about 11 or 12 amps passing through the light switch, quite a load for an old worn switch which, of course, is where relays are useful.
Bill
Bill Bretherton

This is Paul Hunt's take on headlamp relays, from his mgb-stuff website.

http://www.mgb-stuff.org.uk/electricstext2.htm#uprated
Dave O'Neill 2

Hi Ray,
let me just firstly put that I'm not a lawyer or have studied the law but I think I'm right in putting that ignorance of a law is not a defense if you break that law so if in doubt don't do it.

I'm happy to answer your inquiry.

I'm not nowadays much inclined to internet debating (or even much micky taking, well most times) but if you email me (first and last name at bt internet dot com) I'll gladly find again what info I can as I don't keep such info "on file" and you can decide for yourself.

Cheers.
Nigel Atkins

Rich, Paul Hunt's Diagram as Relayed (LOL) by Dave is excellent, my changes are to add a circuit breaker in the main feed and take this from the battery or solenoid directly, then use fused relays.
Good luck
Rod
R W Bowers

Issue with led lights is e marking. If they are e marked for road use no issue :)
Rob Armstrong

Rob,
I don't think that's necessarily the case, not blanket cover, see -
http://www.legislation.gov.uk/uksi/1989/1796/contents/made

Nigel Atkins

A Big thank you to you all,
Rob, Steve and J Smith were right it was the wiring at the headlights. both main beam and dip bright as a button now, dash light goes off and new spots working.
All connections and earth checked anyway and I will probably fit relays.

Rich
Rich65

Hi Rich,


Glad we were able to throw some light on the problem!




Seen that so many times, most assume the earth wire must go in the centre connection.


Regards Steve
Steve Smith Midget 1500

This thread was discussed between 21/09/2016 and 26/09/2016

MG Midget and Sprite Technical index

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