intermittent light

[AMY]

Hi everyone, I have a problem where the dip beam on the nearside headlight fluctuautes between working and not. When it does this a buzzing noise can be heard. My initial thought was a faulty relay, as far as I can tell the relay for the lights are contained within the grey relay box on the inner wing. so, so far I have

Changed the relay box
Changed the bulbs
re wired the conectors on the bulbs
cleaned all the earths I could find

Any ideas?

Thanks
Amy

 

[Fordy]

the nearside light isnt working because of the contacts in the light stalk on the steering column change this with a good one or repair it by pushing the contacts down on the back behind a white plastic cover,

i will have to make a guide on this i think seems to be alot of people with this fault

dont know about your buzzing noise tho

 

[AMY]

That's about the only thing I havn't checked, how does it only affect the one side? Is the contact at the base of the stalk in the bit that clamps to the column or is it within the twisty bit that you turn to activate the light?
I think the buzzing is because the relay is getting a low or intermittant voltage which is causing it to fluctuate between off and on.

 

[Fordy]

the you turn to to turn the headlights on, the complete stalk, take off the steering column cowling should be 4 phillips that hold it on., look for a white plastic plate thats held on by 4 plastic points on the light stalk, use a screw driver to remove the plastic cover and then you should see a quite few copper strips, turn the stalk to dip beam and you will see that 2 copper strips go down, press each of the 2 copper strips that went down and the headlight that isnt working should turn on this copper strip is the one needs slighty bending down or the contact point cleaning with a nail file

if you want i will get some pictures tomorrow night of the copper strips and plastic plate its behind

 

[AMY]

That would be great, thanks

 

[andrewb150]

Funny mines started doing that sometimes as well. Seems to work if I switch it onto main beam then back to dipped.

 

[Fordy]

sorry everyone ive been busy at work, i will get the pictures/ guide tomorrow for you all

 

[SammoHung]

Yes, I have to scrape my contacts at least once, somtimes twice per year as part of my routine.

The same effect can happen even if the contacts are clean though (as I found out after thoroughly cleaning / scraping the contacts).

The bottom line is...if the series resistance ANYWHERE in this switch circuit rises above a certain level (i think I measured around 120 ohms) get ready for a buzz).

For example, a crusty contact between a headlamp bulb and the spade crimp can also cause the buzz (experienced it!).

The relay buzzez because although there may be just enough voltage to pull the relay coil in (with crust) when the relay coil comes in current flows in the coil circuit. The crusty joint then heats up in its center, the resistance of the crust then rises sharply causing a voltage drop accross the coil....and the coil drops out again. the crust cools, resistance drops and so the cycle begins.

The whole shabang happens very fast resulting in the buzzing

bzzzzzzzzzzzzzzzzzzz

Typical,... you only discover it when you need your lights to work!!

 

[AMY]

I've just bridged the terminal from the working light for the minute, it seems to work OK.

 

[andrewb150]

Yep top marks the problem was in the stalk contacts!! I found it easier to unscrew and unplug the stalk (which was straight forward) and then clean it inside.

Thanks

 

[Fordy]

i cant find the stalk in the garage amy so when i clean out my garage on friday or saturday i should find it then i will get some pictures up

 

[SammoHung]

This time around (about 3 months ago I think) when buzzing started again...I replaced my headlight terminals and housings...this fixed the problem without scraping the stalk contacts this time..

I think this is proof that the problem is caused by the "sum of resistances" caused by corroded and burned/ pitted relay contacts etc. when the sum is greater that a certain level + BUZZZ

keep all contacts tip top and job will be a good un!