Technical weirdest headlight problem

[Violetlexy]

A few days ago the headlights (both of them at the same time) began flickering when I start the car, then stopped and worked normally after a few minutes. I thought maybe it was because of the cold spell. It has been getting down to -20 degrees at night and we do not have a garage.

Two days ago, the lights stopped coming on at all. I checked all the fuses and everything is fine. I took it to a shop where they checked all the grounds and they are all fine too. They ran diagnostics and could not find a problem.

They started to check all the fuses again, and here is the weird part: when the fuse at spot 3 is removed, the headlights work again. Replace the fuse, and they stop working. Fuse #3 is for the Rear fog lights, Rear fog lights warning lights, and Side / taillight power. We also noticed that the rear licence plate lights also went out with fuse #3 removed. What the heck does this mean. Can anyone shed some light?

 

[momoe]

Fusebox can suffer from corrosion, you need to check that there is no corrosion, fusebox can be taken out fairly easily (There is a fairly recent thread on this forum)

Other than that I'm stumped, not heard of this before.

You'll be down to tracing wiring from headlight switch to relay, although I would double check earths.

 

[Violetlexy]

Could it be something to do with a relay or diode?

 

[momoe]

Can't see how a relay would cause the problem, diodes are normally found in the alternator and if faulty would affect battery charging, your battery appears to be ok.

Headlights use a relay to avoid heavy power loading through the switches, headlights draw about 9 amps, so the headlight switch only activates a relay (effectively a remotely operated heavy duty switch) which then supplies the 9 amp power to the headlights.

Headlight fuse should be on the relay side.

The only other thing that springs to mind is there may have been a previous wiring fault and the wiring is non-standard.

 

[BikeDoc]

...Can anyone shed some light?

Whether that was an intentional pun or not...nice one

Could be a short somewhere, between the headlight circuit and the one supplied via fuse Nr.3.
Do the headlamp bulbs glow at all with just the Side-lights on?

Does High-Beam work normally?

 

[Violetlexy]

Ok, I am still having the headlight problem. I want to clarify a little because I realize there was a semantics problem. The headlights that are the problem are the "dipped beam" headlights. The brights or "main beam" headlights still work. I'm not sure if that makes any difference to anyone, but I didn't understand that in the manual. A couple other things:

I changed the rear licence plate lamps a few days before the problem because one of them was burnt out. I changed them to led lamps from the standard. Could this be related? Remember that the fuse #3, the one that makes the headlights work when removed, is the fuse for the rear plate lights.

Does anyone have any suggestions on how I can temporarily circumvent the problem until I figure it out?

 

[BikeDoc]

Weirdest headlight problem

Fitting the LED lamps wouldn't affect it, the only electrical difference to standard bulbs is that they take a lot less current.

To put your mind at rest, remove the Reg-plate bulbs and try the head-lights.

The High Beam circuit should be served by a different fuse to the Dip-beam.

You could try removing all the bulbs supplied via the Nr. 3 fuse circuit, and disconnect the Fog-light switch if you can, then see if the problem is still there.

Take a look at the wiring in and around the rear light clusters, checking for any corrosion in the connectors or on earth points.
Also check to see if any wires are chafing (rubbing) against any metal parts, or each other.

 

[Violetlexy]

Thank you to everyone who replied. After spending more than 3000 nok (!!) the guys finally figured out it was in fact the relay. All they did was shake the thing, it made a noise like something was loose in there, then they then gave it a tap or two and put it back in and it worked. arg :bang: there goes the Christmas presents kids. Anyway we will order a replacement and install it to be safe. Thanks again for the help everyone.