740 day running lights

A small problem: The "knackered bulb" indicator in the car is lit but goes off if the sidelights or headlights are switched on, indicating a fault with a day-running light.

One day-running light is brighter than the other because *both* filaments (stop and tail bulb - 21w/5w) are lit and the other only has the 5w filament lit. If I turn the sidelights on then only the 5w filaments are lit, both sides. The bulb *looks* fine but I haven't got a replacement to hand, nor a tester, which is at someone else's house at the moment.

Are both filaments supposed to be lit when the day lights are on or just the

21w one?

Si

Reply to
Mungo "two sheds" Toadfoot
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Hard to tell as you get reflection from the 21 to the 5 but I am sure only the 21 should be on; failure of the 21 is the commonest fault.

Reply to
Steptoe

I'm fairly sure they were both lit but I could be wrong - it's difficult to look at a 21w bulb!

If they *are* both lit any idea why this might be?

Si

Reply to
Mungo "two sheds" Toadfoot

*Thinks*

Dodgy wiring, switch, or holder, innit? Bugger. I hate electrics.

Si

Reply to
Mungo "two sheds" Toadfoot

You've probably got a bad ground connection at the light.

Reply to
James Sweet

You might be right. I just got in the car and the warning light has gone out! It's been coming on intermittently for the past few weeks but decided it was staying on for good recently. Until this evening. Ho hum.

Si

Reply to
Mungo "two sheds" Toadfoot

It is a well known fault of twin filament bulbs that when the earth connection doesn't quite make good then the other filament acts as an earth contact. The bulb itself can also fail as a Pontiac GTO owner I diagnosed for will tell you.

All the best, Peter.

700/900/90 Register Keeper, Volvo Owners Club (UK).
Reply to
Peter K L Milnes

Sounds like classic symptoms of an earth fault.

Reply to
SimonJ

"Mungo "two sheds" Toadfoot" skrev i meddelandet news:o62dnT-g6aaZFM snipped-for-privacy@pipex.net...

Yes, both are supposed to lit. I am 100 % sure, i do have the Volvo electrical diagram book for that car. I guess Volvo made a shortcut in the design, otherwise they would have had to arrange with an extra relay to turn the filament for the parking light off when the day running light is on.

/aw

Reply to
Anders Wiklund

Seems they would have just arranged the headlight switch to turn off the small filament, that's how it is on cars without DRL, the parking lamp filaments are only on when the switch is in park or headlights. When I added DRL I used a relay to turn them off whenever the parking lamps are powered since my headlight switch doesn't have provisions for them, it does have blank spaces where more terminals could have gone though.

Reply to
James Sweet

iirc they use a special bulb, NOT a stop tail (very similar)

Reply to
mrcheerful

"James Sweet" skrev i meddelandet news:XhC4f.5922$W32.3866@trnddc06...

Rear lights is also on with DRL so they would have had to separate tail and front parking lights.

What is the problem?

The solution has one bonus: When the 21 W filament goes out there is still some light from the 5 W.

/aw

Reply to
Anders Wiklund

yes it's normal, I had an old Saab 99 and both filaments were lit. I much preferred those DRL's to the permanent headlamp ones.

Reply to
john

My C reg 740 had double filament dlrs. the 21w lit with no other lights on and the 5w lit when headlights were switched on. My G & J reg used single filament 21w bulbs that go out with headlights on.

Reply to
Stuart Gray

The Canada Safety Council disagrees with your preference and option provided by OEMs. They prefer normal headlights on. The purpose of DRL is help make an oncoming driver aware of your presence on the road. Regardless of the cost of the bulbs it is very inexpensive if it prevents an on coming car from getting in your way. An accident between on coming cars at closing speed of 225 KPH or 140 MPH would not be a very pleasant experience even in a Volvo.

My Volvo setting is "headlights on". Day or night I do not think about headlights at all. One less thing to remember

Reply to
Gunner

The message from "Gunner" contains these words:

Though research is now being conducted into whether the unintended consequence of this is that drivers concentrate more on the cars with lights and fail to notice pedestrians and bikes. Early indications (IIRC) show that this is the case.

Reply to
Guy King

Eh?

I think you'll find that DRL are better than OEM headlights. Headlights are for when it is dark, period.

Hammo

On 18/10/05 10:16 PM, in reference to snipped-for-privacy@comcast.com, going by the name of "Gunner" wrote the following:

Reply to
Hamish Alker-Jones

Hamish Alker-Jones ( snipped-for-privacy@ihug.com.au) gurgled happily, sounding much like they were saying :

Better in what way?

No, they're for when you need to be seen, as well as for when you need to see.

Reply to
Adrian

The message from Hamish Alker-Jones contains these words:

That may be true in Australia, but in the UK it's different.

Rule 201: You MUST use headlights when visibility is seriously reduced, generally when you cannot see for more than 100 metres (328 feet). You may also use front or rear fog lights but you MUST switch them off when visibility improves.

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Reply to
Guy King

"Gunner" skrev i meddelandet news: snipped-for-privacy@comcast.com...

Dipped light isnt designed to be seen they ar for seeing. This problem is obvious with Xenon lights, they have poor visibility. Maybe thats why Hella has introduced DRLs:

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Reply to
Anders Wiklund

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