Another Headlight Problem

[chopper79]

Hi

I wonder if any members may be able to shed some light in this issue.

Headlight rocker switch to the first position, side light on and working

Headlight rocker switch to the second position, dipped beam on and working.

Main beam flash switch working.

Main beam latching switch when engaged switches headlight dipped beam back to just side lights? - I have changed this switch for a new one in case it was a faulty switch, which has not resolved the problem.

I have checked the fuses which are all fine.

Any other suggestion would be welcome, the model is a sigma roadsport if this help.

Christian

 

[Jonathan Kay]

There's another very similar problem on the go at the moment.

Any recent work nearby?

It's probably the relay, but I'd go through the circuit systematically with a meter. And I wouldn't assume that the new switch works: it probably does but it's a good idea to check it.

Have you got the appropriate wiring diagram?

Jonathan

[chopper79]

Hi Jonathan 

Thanks for your prompt reply.

I have the wiring diagram thanks, I will crack the multi meter out. There has been no work near by, so may just be the relay or dodgy switch, are these both susceptible to failing?

Regards

Christian

[John Vine]

When the dip switch is toggled to high beam, the dipped beam will go out -- that's normal.

As the dipped beam works ok via the light switch, that suggests to me that the relay is also ok?  I could well be off-beam here, but my reading of the wiring diagram shows just the one power output from the lighting relay, namely U107.  This runs to the dip switch and thence to high/low beams.

I may well have this completely wrong, but if not, I'd be checking the high-beam circuit starting at the dip switch.

JV

[Jonathan Kay]

I've read that excellent description again and I think that John is right. Sorry.

I'd be checking the high-beam circuit starting at the dip switch.

Agreed. Identify all the connections on the switches and trace where 12V is appearing as you switch them and where it isn't.

Jonathan

[Jonathan Kay]

There has been no work near by, so may just be the relay or dodgy switch, are these both susceptible to failing?

Compared to ordinary cars my impression is:

• Earth faults are more common.
• Relay contact and seating problems are more common.

In addition:

• There's a known problem inside some hazard warning switches. It can be intermittent and can sometimes be temporarily fixed by cycling. It can reveal itself by faulty operation of the indicators.

Jonathan