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MG Midget and Sprite Technical - Wiring help - no headlights

Hello all,
I suddenly have no headlights and no idea why. Except, of course, that Lucas is involved, which should explain everything.
I have parking lights all round; dash lights, brake lights, reverse lights, boot/trunk light and indicators all functioning as they should. High beam on passenger side only.
I checked the switch and it seems okay, I guess it must be or I wouldn't get parkers and high beam (albeit one side only). All original wiring (as far as I know) and no relays/fuses.
Any ideas where I should look? I don't have a meter (volt meter/amp meter) and never used one. Should I just bite the bullet and book in to an auto-electrician?
Steve
gusangora

I'm not familiar with the Mk 1V but lighting problems of this nature,are often down to a poor earth connection.Hopefully, someone with Mk1V know-how will be along soon !
M J Chapman

Blue wire with a white tracer is high beam
Blue wire with red tracer is low beam

I think you may have a couple of problems here. If you have at least one headlamp then the headlamp power to the dip switch is OK (Blue wire) So perhaps you have one faulty headlamp filament
And also perhaps have a faulty dip switch which is not powering your dip beams.

If you go to the headlamp loom and check for 12 volts between the Blue/red wire to earth when the dip switch is on dip. If you have power there then either your filaments have failed or you do have a bad earth
Bob Turbo Midget England

I'm with Bob on his diagnosis. Most likely scenario:

(a) You have two faults. Your high-beam filament on the driver's side headlamp bulb has blown. You also have either a switch fault (on the stalk switch that toggles between dipped and main beam) or your blue/red wire is damaged or faulty as it leaves the stalk switch.

Less likely:
(b) You have two (even less likely, three) faults. You have a bad earth on your driver's side bulb (resulting in no illumination of either the dipped or main beam filaments of that bulb). Also, your dipped beam filament has blown on your passenger side bulb. (And, you may even also have no power on your blue/red wire leaving the stalk switch).

If I recall, the toggle function for the headlamps' dip/main operation (on the stalk switch) relies on a tiny copper contact that is formed in the shape of a bent 'L'. That contact is a poor design, and can loosen with age.

Also, if you've been running headlight bulbs with wattages higher than 55/60, that contact can get hot and melt the plastic anchoring point that holds it in the stalk switch.

As Bob states, the fact that you've got one headlight bulb filament lit does suggest that you've got power entering the stalk switch. IIRC, there are no fuses in the headlamp circuit (a nasty design!)
Andy Hock

Thanks guys. You are correct, there are no fuses. I do intend to add relays and fuses, so this is probably a good time.
I will access the stalk switch tonight (after work) and see what I can find.
Thanks,
Steve
gusangora

Steve,
The fact that one high beam is working means that your headlight switch is working. That's one good thing. There are only three reasonable suspects for the other high beam not to work:
1. Blown filament
2. Bad bullet sleeve
3. Bad earth

Might as well pull both headlight bulbs and try swapping them. this should address the possibility of a bad bulb.

Both the blue/white and the blue/red wires come to the front of the car and then split at a double bullet sleeve in order to feed two bulbs. Only three wires come out of this double sleeve; one from the dip switch, one to the RH headlight, and one going across the front of the car to a single bullet sleeve feeding the pigtail to the other headlight.The metal conductor inside the sleeve is known to split and become ineffective at conducting current. Here in the USA, it is easy to acquire a small round brass wire brush intended to clean the bore of a .22 or .177 rifle, ideal for cleaning the inside of a bullet sleeve. A bit of steel wool does wonders for the bullet itself. Some dielectric grease, readily available at your FLAPS, helps postpone the need to repeat the process. A good supply of new single and double sleeves is also a good idea. There shouldn't be any more bullet sleeves in the headlight power than the ones mentioned above. Luckily for you, there are NOT any up under the dash where the front wiring harness connects to the rear wiring harness and the dash wiring harness; those require special forms of profanity.

The earth leads are also bullet-sleeved together, so there goes a bit more elbow grease.
David "see attached diagram" Lieb


David Lieb

Steve,
I think it has been said, but I would first swap the working mainbeam headlight bulb to the opposite side. This will confirm if the fault on the non-working side is bulb or wiring. I suspect it is the bulb.

For the non-working dip, the most likely cause is that the blue/red trace wire has broken off its brass terminal inside the column mounted switch. They can be re-soldered quite easily.

If the switch is the original Lucas one don't throw it away lightly, without attempting a repair. The commonly available replacement ones look OK are of a far lesser quality and are unlikely to last as long as the original Lucas one.
Guy

You can clean up the sliding plate in the old switches... even spin it round so different parts make contact. Most of the wear is from sparking when switching off; when corrosion is bad, then the contact is poor and the switch heats up around the contacts which can sink in to plastic - these become much more difficult to repair.

A
Anthony Cutler

Thanks guys. It looks like it will be Friday before I get a chance to sort this out. I will keep you posted.
Steve
gusangora

Update: the problem with the right high beam was a loose bullet connector, easy fix. The low beam (or standard) headlamps have no power coming from the stalk. I have temporarily connected the high beam power to the low beam headlamps, so now I have headlights but no high beam (never use them, anyway) until I sort out the stalk issue. I have pulled off the steering column cover and can't "see" anything wrong, so will now dismantle and investigate further.
The indicator stalk is only one year old, so surprising that it's faulty already.
Also, whilst removing the cover, I noticed that the steering column has quite a bit if movement forward and aft, ie. it pulls out toward the driver - is that normal?
Steve
gusangora

>>The indicator stalk is only one year old, so surprising that it's faulty already.<< unfortunately it's not surprising, get a replacement or your money back if it's under 12 months old (assuming you get 12 month warranty with it)

Now you can see that the old Lucas stuff wasn't that bad, switches lasting 20-40 years rather than 10 months

>>Also, whilst removing the cover, I noticed that the steering column has quite a bit if movement forward and aft, ie. it pulls out toward the driver - is that normal?<< no it's not

(don't suppose Aus models had collapsable steering columns anyone know?)
Nigel Atkins

Steve, If your steering column pulls up and down away from the dash check that the pinch bolt where it secures to the steering rack is still tight. It is one of the important "regular check" items. The pinch bolts do work loose, and depending which way in it is inserted the bolt can potentially drop out, leaving you with no steering and somewhat out of control of the car.

As I mentioned before, the aftermarket replacement stalk control switches look OK, but are made of poor quality metals. The little leaf spring things go soft and loose their springiness, the contacts burn out and the brass terminals go brittle and snap. Check to see that the blue and red wire (dipped beam) is still attached to its terminal. Also look to see how the contacts work between the main and dipped beam settings. You may find that a bit of bending restores operation, at least for a bit.

Best solution with these low quality switches is to add relays for the lights so that the switch itself doesn't carry too much current. They then survive for rather more than just one year!

Guy
Guy

Guy - you were correct, the pinch bolt was loose. All fixed, thank you.
gusangora

okay, I'm still working on the headlight problem, haven't fiddled with the indicator stalk yet. I thought that I would install relays first, then tackle the stalk issue (my temporary fix had given me low beam headlights, just no high beam).
I have purchased relays, fuses and cabling etc but have a question regarding the negative/earth wire from the headlamps. The current/original setup has this connected to the car body but I read somewhere that it is better to take the wiring back to the alternator or battery, so should I do this or is the car body adequate?
gusangora

If you have an early car you have the foot switch to operate the highbeam. Rock that switch for 10 times and probably your normal beam starts working again.

Bas
Bas Timmermans

I ended up wiring to the car body and relays are working well - step one complete.
I had another look at the indicator stalk and can't "see" anything wrong however the issue certainly seems to be here. I experimented by wiring a "jumper" cable between the power in and power out (blue and blue/red), and headlamps came on.
I probably need a new indicator stalk however I have a question regarding its operation: when I push the stalk forward, to activate high beam, does low beam continue to receive power? that is, does power go to both high and low when high beam is active? If so, then can I solve my issue by simply soldering a jumper cable and bypassing the indicator stalk?
gusangora

No when you select high beam low beam will be switched off.
Robert (Bob) Midget Turbo

Thanks, thought that might be the case. Now I am thinking that it will be cheaper and more permanent to bypass the indicator stalk and install a separate switch for high/low beam on the dash (or near/under).
I'm thinking that I could take power from the light switch (blue wire), then have a simple switch whereby one contact is blue to blue/red and the other is blue to blue/white. I could leave the 'flasher' on the stalk (splice in the blue/red wire). I just need to determine which wire is for the blue light in the speedo, to indicate whether high beam is active.
What do you think?
Alternatively, what are the problems with having both high and low active at the same time? Is it just bulb life? Would excess heat be an issue? (nothing to melt other than the lamp holder connector). Remember, I hardly ever use high beam.
Thoughts?
gusangora

Hi Gus

Struggling to understand how you could wire the original switch so that in one position you get dip beam and in the second position you would get dip and main? IMO if you wired the 2 together you would get both on all the time!!

A seperate switch would do as you have described with a connection from the blue and white wire to the high beam bulb in the speedo
Bob Turbo Midget England

If I connect the blue to the blue/red, then dip/ low beam will be on as soon as I flick the rocker light switch (irrespective of indicator stalk position) and will remain on when I push the indicator stalk to activate high beam.
gusangora

Why have you given up on the column switch? Take another look at it. To understand how it works. It is easier to see if you remove it from the column but keep the supply cable connected.

Check that the blue / white is still connected. Look at the small contact terminals. One one side of the unit there are 3 in a row that form the switch for high beam on, off, and flash. The little thin metal supports for the terminals can get bent if they have overheated at some time, so that they don't contact when they should. Some careful prodding with a small blades screwdriver should correct it.
Guy

Hello Guy,
I did take the column switch off the column and examine carefully, whilst observing it's operation. Pushing forward to main/high beam works, as does pulling to flash. I can see the contact points making contact and then moving away. What I can't see is any movement to separate power/break contact away from the dip/low beam. That part of the column switch doesn't appear to have any movement. And the parts seem to be in constant contact. I have fiddled and prodded with a small blade screw driver but it doesn't appear to make any difference. And all wires and correctly and securely attached.
gusangora

Hi Gus.
It does then sound like a faulty one!

If "jumping"b the power in and the power out at the column stalk switch gets them working, then the fault must be a break in the continuity of the internal connection in the switch, or of the contact surfaces. When the stalk is pushed forward for high beam, the low beam contacts should separate, but you say that they don't. Perhaps there is corrosion on the surfaces that is preventing them from parting company, but also providing too much resistance.
The contact "buttons" are pretty small and do tend to corrode, especially if they have been carrying a high current (a good reason for adding your relays) Maybe they need cleaning up with a needle file or a SWMBO nail emery board.
Guy

Isn't there a switch on the dash for normal light and the stalk on the column just for high beam and flash? So when normal lights don't work, what's that got to do with the stalk, except it breaks contact to the normal light. And in this case it does it's job a bit to well.

Or is that different in a 1500?
Alex G Matla

I believe that the dashboard switch powers the column stalk switch from where you can then choose between main, high or flash (which is both, momentarily)The switches are in series.
Guy

Aha.
Alex G Matla

But you are right Alex, one could take a feed direct off the dashboard switch to the main beam relay (or lights) Then they would stay on whenever the dashboard switch was on and the stalk switch would just "add" high beam when needed. But in the UK this would be illegal as the headlights would then be over the legal limit when high beam was on. You have to have it wired either / or, not both. Other than for the flash option.
Guy

Not sure having both lit would be illegal mate. The law states the maximum bulb power somewhere around 65/70 I think but it does not state a limit to how many. Indeed many vehicles nowadays have headlights and driving lights that are continually lit without problems of legality.
Robert (Bob) Midget Turbo

Bob,
Maybe you are right, but I imagine it might come down to interpretation of "maximum bulb power", given that in this case there would be 2 filaments lit within one bulb.

I also suspect, quite apart from the issue of legality or otherwise, that the bulb life would be reduced because of excess heating.
Guy

With both filaments lit at the same time, excess heat could be an issue. Relays would be essential to prevent the main headlamp switch from burning out and the earth returns from the headlamps would probably need to be bigger.
Dave O'Neill 2

Update:
I got myself a small toggle switch, which I mounted under the dash, on the lip, just under the speedo (slightly left, ie toward centre of car). It works well and I now have low beam, high beam and flash
BUT I now have a new problem. Whenever I put the left (passenger side) indicator on (ie stalk up), the fuse blows!
I guess I now have a shirt but don't know where to start.
Just when you think you're winning, they move the finish line!
gusangora

This thread was discussed between 22/03/2011 and 14/04/2011

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