I can’t see the light

[chopper79]

It’s MOT time

I just wanted to check the correct function of the head lights on my caterham sigma 125. Can someone confirm that this is correct

Headlight rocker position 0 = Headlights off

headlight rocker position 1 = side lights on

headlight rocker position 2 = headlights on Dipped

The when the dip toggle is down = full beam.

what I have at the moment is when dip toggle is down = Back to side lights?

the flash toggle still gives full beam flash and the blue light in the tacho illuminates 

I have replaced the fuses, the dip toggle and the relay. But to no avail?

I have the wiring diagram, but still can’t trace the issue. Before I take it to an auto electrician I thought I would see if anyone else had come across a similar issue. I have also search blatchat but cannot find a resolution to the same fault.

Thanks in anticipation 

Christian 

 

[Jonathan Kay]

I'm not sure what's currently happening...

Main switch on 2:
Dip switch up: ???
Dip switch down: side lights only.

And that's consistent between two different dip switches?

And the connections at the dip switch are good, and the wiring colours at the switch match the diagram?

Do you have a multimeter?

First I'd check continuity through both the old and new dip switches switches in both positions 1 and 2 with the wires disconnected. If that's good it gets interesting.

Jonathan

[SLR No.77]

Christian, you've lost your feed to your full beam. When the toggle switch is in the down position, the dip beam will turn off leaving the sidelights on, but your full beam should be on as well. It could be the switch, or IIRC there's a relay. I'd replace the replaceable items (fuse, relay, switch) before messing with wiring and connectors.

Stu.

[chopper79]

I crack the multimeter out and test the switch, old and new. It certainly is baffling.

[bjw]

I haven't seen a circuit diagram for the Sigma, but in one for an older model the flash feed to the main beam goes 'via' one of the terminals on the dip switch, i.e. a wire in and a wire out of the same terminal.

If those wires are still connected together within the terminal block, but the contact with the switch terminal itself is broken, that would create the problem exactly as described.

Such a fault would also remain after changing the other components mentioned.

Cheers

.

[chopper79]

Problem solved and a little Caterham lesson learned. If in doubt get the multimeter out!

The original fault was due to a faulty toggle dip switch, a replacement was installed which also was faulty, third switch lucky after testing for continuity has solved the problem.

I probably could have saved some time by checking the first replacement and not assumed that because it was new it would work!

Thanks for all your help chaps, most appreciated.

I can see the light! 

[Jonathan Kay]

Well done.

The original fault was due to a faulty toggle dip switch, a replacement was installed which also was faulty, third switch lucky after testing for continuity has solved the problem.

That was unlikely, but as long as one of them was in the circuit and involved in the diagnostic procedure it needed to be excluded.

If in doubt get the multimeter out!

:-)

Jonathan

PS:  I get the prop shaft UJs greased while it's up on the lift at the MoT.

 

[bjw]

Glad to hear it's working, but the odds of a brand new switch having the exact same fault are so very far beyond unlikely that it might be worth another test.

It may seem overly cautious, but it's only a couple of minutes work to swap the second switch back in to check the fault re-appears, and it means it won't come back and bite you again later !

Cheers

.