MG ZT: Both dipped headlights dim

[mkellerman]

I just bought an MG ZT KV6 with halogen headlights.

The main beam headlights work well, but both dipped lights are equally dim (but a bit brighter than when I only turn on sidelights). The main beam lights look white when switched on, but the dipped beam lights look yellow.

I shined a torch into my headlights when they were switched off and the reflectors in all 4 headlights look equally silver, so I do not think the problem is corrosion of the reflectors or misting of the glass.

Possible causes I am thinking of are:
1. Bad ground connection (but the lights on both sides are equally affected)
2. The bulbs in both sides have acquired a brown coating inside the bulb due to age and need replacing
3. The dashboard switch has degraded

Does anyone have any suggestions of how to troubleshoot this, or likely causes?

[T-Cut]

I'd replace the bulbs as a starter. If there's no improvement, then it's likey to be an electrical issue, bad earth, faulty wiring, etc. Also remember that the lighting harness can be chafed by the body seam, driver side.

https://www.mediafire.com/convkey/c1fe/1bwuk0igo872o156g.jpg

TC

[mkellerman]

Hi T-Cut,

Thanks for your reply. Yesterday, I tried using an old toothbrush and toothpaste to polish the outer surface of my headlights and that improved it quite a lot when I took it for a test drive last night--but the dipped lights are still not bright enough for my satisfaction.

I think the plastic lens of my off-side dipped light may also be misted on the inside. Is that possible?

On closer inspection of the lights, it seems the reflector inside the lights might be a bit yellowed at the edges.

I plan to buy Osram Nightbreaker Laser bulbs. Probably this will be enough to sort things out. My benchmark is that if I can see adequately on a pitch black road with dipped headlights when going at 30mph, the brightness of the lights is normal.

[madeupname]

Hi Martin. I think most of our cars have this problem. Both mine do. Advice on other threads to do with this is to replace the bulbs with brighter ones. Rick-Sta is the one to ask about headlights ;)

[mkellerman]

Hi Martin. I think most of our cars have this problem. Both mine do. Advice on other threads to do with this is to replace the bulbs with brighter ones. Rick-Sta is the one to ask about headlights ;)
Thanks! Night Breakers are now ordered.

I was in my friend's 2009 S-Max tonight. The dipped lights gave a clear view of a dark road even at 50mph. It really made me realise how poor my dipped lights are, but anyway, here's to hoping the brighter bulvs do the trick.

Also, I was thinking if I take the old bulb out, might I be able to poke something in there to clean up the lens from the inside? Has anyone done that?

[madeupname]

There should be a rubber cap on the back of the headlights. If this is missing it could lead to condensation.
It might be more worthwhile taking the bumper off, then taking off the headlights and cleaning them indoors. But remember to get the beam alignment checked when you put them back on cos it might have moved ;)

[TomRS]

Thanks! Night Breakers are now ordered.

I was in my friend's 2009 S-Max tonight. The dipped lights gave a clear view of a dark road even at 50mph. It really made me realise how poor my dipped lights are, but anyway, here's to hoping the brighter bulvs do the trick.

Also, I was thinking if I take the old bulb out, might I be able to poke something in there to clean up the lens from the inside? Has anyone done that?

They run Xenon's so you cant really compare the two.... but personally i'd fit an eBay HID kit to your projector's as this will give you a hugely improved light output.
They are about £15-£30
Something like this - H7HID (https://www.ebay.co.uk/itm/Hid-Conversion-Kit-9006-H1-H3-H4-H7-H11-9005-Xenon-Headlight-Bulbs-55W-Ballast/262602272789?hash=item3d2450b015:m:m5xGUImY6DBCBYh 2hQGZdmg)

[mkellerman]

One strange thing I noticed today is that the yellow label on my radiator support that tells you about the aircon gas to use and the coolant to use, also says "xenon handlamps only", but my headlamps are halogen. Does anyone have any idea why this might be?

[suzublu]

One strange thing I noticed today is that the yellow label on my radiator support that tells you about the aircon gas to use and the coolant to use, also says "xenon handlamps only", but my headlamps are halogen. Does anyone have any idea why this might be?

It's a one sticker fits all thing, all the cars have them:cool:

[mkellerman]

It's a one sticker fits all thing, all the cars have them:cool:
I see. That's odd, since the car does not have Xenon headlights...

I guess it is just a vagary of MG, then...

[COLVERT]

Are you sure it says HANDLAMPS ???---:shrug:

[mkellerman]

Are you sure it says HANDLAMPS ???---:shrug:
Well spotted.

Today I put in the new Night Breaker bulbs I bought. I used the access hatches in the wheel arch. The off side went pretty smoothly, but on the nearside, it seems the clip that holds in the bulb was not there. Maybe that is why the nearside light has been particularly dim--perhaps the bulb was not completely inside the headlight.

Two questions:
1. When I put the new nearside bulb in, it brushed against the various cables that are in there. It seems halogen bulbs can get destroyed if turned on when there is any moisture on them. Because of that, I did not dare to turn the lights on after inserting the bulb in case there had been any moisture on the cables. If I leave the bulb for 24 hours, do you think it will be safe to turn it on?

2. As the clip seems not to be there, in order to make sure the bulb stays inside the headlight properly, I am thinking of putting a jam jar lid inside the round rubber cover that goes on to the back of the headlight behind the bulb. Any thoughts on that?

[Avulon]

Well spotted.

Today I put in the new Night Breaker bulbs I bought. I used the access hatches in the wheel arch. The off side went pretty smoothly, but on the nearside, it seems the clip that holds in the bulb was not there. Maybe that is why the nearside light has been particularly dim--perhaps the bulb was not completely inside the headlight.

Two questions:
1. When I put the new nearside bulb in, it brushed against the various cables that are in there. It seems halogen bulbs can get destroyed if turned on when there is any moisture on them. Because of that, I did not dare to turn the lights on after inserting the bulb in case there had been any moisture on the cables. If I leave the bulb for 24 hours, do you think it will be safe to turn it on?

2. As the clip seems not to be there, in order to make sure the bulb stays inside the headlight properly, I am thinking of putting a jam jar lid inside the round rubber cover that goes on to the back of the headlight behind the bulb. Any thoughts on that?

1. Switch it on - it'll be fine unless the whole inside of the lamp is wet?
2. NO! Don't do it. It won't hold the bulb in place properly - the cover is only a light push fit, and doesn't (shouldn't) be touching the bulb. Also (you may not be aware of this) whenever you switch on the lights move full the motor adjust range so it'll be rubbing against the bulb wiring. Get or improvise a clip, it's only a bit of stiff wire after all. Either adapt one of the ones from Halfords (they look pretty close to correct) or bend one out of one those giant paper clips.

Also. Make sure the bulbs are the right way up in the holders.

Question: on your projectors looking at the inner projector lens, is it cloudy looking or clear?

[minimutly]

Irresepective if the nightbreakers have cured your dim light problems, you need to order some more - they won't last the winter.
All rovers have been plagued by poor lights since the days of the sealed beam - it seems certain german manufacturers were allowed light outputs set to dazzle anyone, sadly rover must have been playing by different rules...

[mkellerman]

1. Switch it on - it'll be fine unless the whole inside of the lamp is wet?
2. NO! Don't do it. It won't hold the bulb in place properly - the cover is only a light push fit, and doesn't (shouldn't) be touching the bulb. Also (you may not be aware of this) whenever you switch on the lights move full the motor adjust range so it'll be rubbing against the bulb wiring. Get or improvise a clip, it's only a bit of stiff wire after all. Either adapt one of the ones from Halfords (they look pretty close to correct) or bend one out of one those giant paper clips.

Also. Make sure the bulbs are the right way up in the holders.
Is this to do with the electrical polarity, or the optics? How do I know which way up they should be?

Question: on your projectors looking at the inner projector lens, is it cloudy looking or clear?
I polished up the outside of the lights, but I think the inside is rather cloudy too.

[Avulon]

Is this to do with the electrical polarity, or the optics? How do I know which way up they should be?


I polished up the outside of the lights, but I think the inside is rather cloudy too.

Optics: The bulb will only seat properly in the correct orientation so won't be in the right position otherwise.

If the inner projector lens is cloudy then this will be detracting from the light output - mine are a little cloudy and with halogen bulbs in they seem (to me) incredibly dim. I hope to get around to giving mine a proper clean at some time.