Headlight problems

S

Steve C

Member
Hi, p62000tc, Im at a loss with my headlights, if i select headlight ( dip) both outer lights come on as normal, when i the select main beam, all lights come on as normal, but after about 15/20 seconds, the off side outer and near side inner go out, the remaining two stay on.
If I then switch back to dip the off side outer comes back on ( thus both outers on), ive checked all the connections that i can reach and all seem ok.

the above problem happens every time I select main beam, cant understand how the problem starts after 15/20 seconds?

any advice here would be great.

Regards Steve.
 
Most likely you have bad connections in one of the bullet connector blocks, and it’s heating up and then going open.

Keep in mind that even though the outers light on high beam and low beam, they are using different filaments. Your problem seems limited to the high beam circuit.

Series 1 or series 2 car?

Yours
Vern
 
Sounds like the fuse box is overheating, be careful it can catch alight.

The springiness in the brass contacts is actually made by the plastic, not the brass, so as they heat up they can lose pressure.
 
Many thanks for the advise, Vern my car series 2, I have rechecked all the bullet connectors, they are all dry and rust free, Quattro, I don, have been checking the fuse box and don,t think it is getting hot. Paul have read your thread, and take note of the relays etc, but my problem at the moment is slightly different, in that the problem only occurs after 15/20 seconds and not straight away
I am now thinking that the problem may be the twin filament bulbs in the outer lamps. my train of thought is that the outers work fine when only dip beam is selected, but when switching to main beam with both filaments now heating up, could they be touching as they heat and expand, I seem to recall a similar problem with twin bulbs at work many years ago,.
will get a new set of bulbs at the weekend and try out my theory
Regards Steve.
 
"I have rechecked all the bullet connectors, they are all dry and rust free,"

The brass in the bullet connector sockets, particularly the 4 & 6 hole ones, gets brittle and breaks. The result can be no contact/poor contact, even though the bullet is retained and a multimeter shows continuity.

Yours
Vern
 
just one more stupid question, my outer lamps have bulbs but the inners are sealed beam, could this be causing a problem.

this lighting issue I have could have been present ever since I have owned the car, ( about a year), have never been out at night, and when checking the lights in the past have just switched them on , had a quick look and switched them off, lights play up after about 15/20 seconds, thus never realised the problem was ever there.

Regards Steve.
 
Hopefully now sorted, still not sure what the problem was, checked and cleaned all fuses, ( no sign of any melting or getting hot), checked all bullet connectors, replaced both outer bulbs, and now all lights seem to work correctly, will leave the passenger knee bin off for a while until Im sure its ok. Still cant work out how every thing worked normally for 15/20 seconds then failed every time.

regards Steve
 
The 15-20 secs thing does sound like a heat thing - high beam pulls quite a lot of amps, and the S2 fuse block is known for melting issues, especially at the headlight fuses - mine has signs of melting there. Relays are your friends here.
 
The plastic on the series 2 fusebox is made from a plastic called, 'easymelt.' This is a picture of my fusebox a few weeks after I bought the car.

Melteda.JPG

The 15A one on the right is correct, being the right length and fitted correctly. The middle one is too short, meaning the top has just over half the contact that it should have. All of the power going through is using around 60% of the contact area and is therefore causing heat build up.

The plastic shapes each side of the brass contacts are what gives the fuse holder its spring, as the brass contacts are not a single piece, but two separate 'spades,' as below.

IMG_6146.JPG

If the fuse gets hot from poor contact because of dirt, wrong size, age, badly wired accessory, or any other reason, the plastic can become soft and so lose its springiness. This can cause either a worse contact creating more heat build up and maybe a fire (or it melts as mine did), or break the contact completely so your lights go out.

Best to check the fuses are the correct length (1 1/4" - 32mm) and not 30mm, make sure they are clean and not tarnished in any way, and check the plastic hasn't degraded or melted so giving a lighter grip.
 
Thank you both for the last replies, and great photos, I have cleaned and checked all fuses, all except one are the correct 32 mm size, (awaiting replacement fuses in post), lots of comments about fitting relays, my electrical skills are very limited, so will be getting them fitted by someone who hopefully knows what they are doing.

Regards Steve.
 
As well as cleaning the fuse ends and the clips, get some Deoxit (or similar contact cleaner) and smear on the fuse ends. Then go around the whole car and undo, clean(abrade) and Deoxit all the earth connections. In the UK climate this is good maintenance EVERY year, especially on cars with low usage.
 
one other place is the actual dip switch. the wire ends are riveted to the contact plate and the rivets can get dirty and not pass the current through to the switch part.
 
Thanks for the advice, all fuses have been renewed with the correct 32mm, and every thing is working as it should.

I fully intend getting relays or a replacement modern fuse box fitted sooner rather than later, as i use the car as a daily driver.

I have been keeping a close eye on the fuses ( knee bin still removed) and using a thermal gun to check the temperature of the fuse contacts, this can range from between 25c up to 40c, depending on what is switched on, ( nothing is even warm to the touch) with no wifs of smoke, melting etc, question is how warm should the fuse terminals get in normal use .

Regard Steve.
 
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