One sidelight not working - troubleshooting

[BenF]

Hello

Whilst attempting my LED headlamp conversion, I noticed that one sidelight was not working.  I was going to use this to power the halo on the LED lamp.  Current checks done:

No obvious break in the loom.

All fuses checked (but anyway unlikely as other sidelight is working).

Sidelight bulb swapped from side to side, confirms it's not the bulb.

Multimeter b*ggered so cannot check in detail until I order another one!

Does anyone have a wiring diagram for a CSR200? (I guess not that different from other 7s).  Anything else obvious to check?  This could be a right pain to get to the bottom of.  At least the main bulb is working...

Ben

[Jonathan Kay]

"Anything else obvious to check?"

The earth. In the absence of a multimeter run a good earth to the bulbholder and see if it makes a difference.

Jonathan

PS: You're welcome to borrow a multimeter... OX44.

[Jonathan Kay]

"Does anyone have a wiring diagram for a CSR200? (I guess not that different from other 7s). ":

Steve Marsh has a nicely curated set of documents for the CSR. I suggest downloading them all while they’re there:

http://www.sjmmarsh.com/7files/Caterham%20CSR%20Superlight%20Suspension%20Set%20up.pdf

http://www.sjmmarsh.f2s.com/index.htm

...

British "standard" wiring colours.

Jonathan

[BenF]

Thanks Jonathan

Multimeter mended - so progress of sorts (thanks for offer).

Any tips on where to start diagnosing, with a working multimeter?  What should the voltage be to the sidelight?

[SM25T]

12V ! Look for damaged or corroded connector at the miltiplug just inside the body.

[SM25T]

Check the sidelight earth connection is intact to the screw in the base of the bowl.

[BenF]

12V.... yes of course, for some reason I thought it should be less for the sidelight.

The earth to sidelight connection is good and this earth connection is also good, as the main headlamp is working.  Plus, the connection from the headlamp bowl to the plug just inboard of the suspension is good, there is continuity.

I now notice that the rear light on that side is also part of the same circuit and also does not illuminate when I switch the lights on (either sides or main), but the brake lights do work.

So it looks like the break is between the connector plug to the headlamp bracket and the fuse box - but unfortunately there is nothing obvious to be seen and it's pretty difficult to test.

I guess I need to be getting a professional to look at it, unless there are any other suggestions.

[Jonathan Kay]

"All fuses checked (but anyway unlikely as other sidelight is working)."

...

"I now notice that the rear light on that side is also part of the same circuit and also does not illuminate when I switch the lights on (either sides or main), but the brake lights do work.

So it looks like the break is between the connector plug to the headlamp bracket and the fuse box - but unfortunately there is nothing obvious to be seen and it's pretty difficult to test."

...

The left side and right side circuits for the position lights might have different fuses... 

... so I'd check those fuses again. And if they're intact the contacts and the connections at the fuse box.

Jonathan

[BenF]

I'm actually having a parallel chat about this on a Beds Bucks Northants Whatsapp chat...

Yes, the LH and RH circuits do indeed have different fuses.  I will double check but I already went through them all once.

[BenF]

Problem solved - the visible part of the fuse itself was intact, but one of the legs was bent sideways and I think there was actually a break in an area you could not see.

So now with a new fuse, all back to normal!  Thanks for the advice and as usual Jonathan is the voice of reason!

I spend a couple of hours trying to solve that problem.  I know the car a lot better now, but could have avoided some stress if I found that earlier.  Have not even eaten yet!

[SM25T]

Well done