Front O/S side indicator wiring - help please

[Grandmaster Flatcap]

My O/S side indicator has packed in. Bulb is fine, crossed checked with N/S holder. Checked with multimeter and +ve supply is good. 

How can I check the -ve? 

Where does the other end of the -ve wire connect to?

[Jonathan Kay]

All other lights OK?

1. Check continuity of the other terminal in the bulb holder to a good earth.
2. Rig a temporary wire from a good earth to that terminal and check that the bulb then illuminates.

Once those confirm the problem work backwards from that terminal through its connection to the wire, then any connectors and so on.

Jonathan

[Grandmaster Flatcap]

All other lights are OK.

The holder is, I think, non standard Caterham and appears to be sealed, so doing your suggested checks may have to be "destructive".

[Jonathan Kay]

The first test should be feasible at the point of contact with the bulb...

What connectors can you find? Should be the black wires.

Jonathan

[Jim 123]

The side indicator -'ve is normally routed into the hedlamp casing and earthed along with the main lights.

[Jonathan Kay]

In that case I'd be looking hard at the connection of both ends of that final earth wire.

Jonathan

[Dr Slotter]

My side repeaters are earthed to the wing stay.

[SM25T]

Normally earthed under the wing on the top stay. Prime spot for corrosion

[Grandmaster Flatcap]

Thanks for the replies so far gents. I'm away from the car until the weekend, so will check then

[Jim 123]

Side repeaters are usually earthed to the wing stay. 

Indicators (i.e. the flashy things under the headlights) have their earth lead routed up the headlamp mount and to the headlamp internals.

[john milner]

The -ve of my side indicators were glued to the wing stays. I extended the wiring to the main chassis and used a bolt somewhere to earth it.
 

[Paul McKenzie]

99% it's a bad earth on the wingstay.  Clean the area to bare metal with a small wire brush in the drill, replace the connector and attach with a new screw. Dab of Hammerite over the lot, jobs a good 'un

[Doug phillips]

Mine stopped working after I had wing come lose, of course I only found out after I had soldered the wires back together

 

The bulb was ok, and checking with a multimeter I had power and a good earth. So something in the bulb holder it's self had broken and was not making contact with the bulb, I just replaced it in the end.

 

[Jonathan Kay]

So something in the bulb holder it's self had broken and was not making contact with the bulb...

Yes. I've had two of those (in other lamps) on the 7, and several others, including, for some reason, a disproportionately high number on tow boards.

99% it's a bad earth on the wingstay. 

Could be.

Could be no contact from bulbholder to bulb, or internal discontinuity in wire, although those are pretty rare.

But why speculate*? See post #2.

Jonathan

* I had a faint hope that the derivation might be through a little reflector, but it isn't. :-(

[Jonathan Kay]

Nigel: is the offending lamp the indicator under the headlamp, or a repeater on the wing or side?

Jonathan

[Grandmaster Flatcap]

JK it's the repeater on the cycle wing.

[Jonathan Kay]

Thanks, Nigel.

Jonathan

[Jonathan Kay]

If it comes to replacement I've got an unused pair. From the factory in 1998, similar to those in the picture but the amber part is symmetrical.

http://caterhamparts.co.uk/img/p/4922-5300-large.jpg

Jonathan

[Paul McKenzie]

"But why speculate*? See post #2."

Because if that isn't the problem now, it will be soon...so look at it as a bit of preventative maintenance at worst, and as I said, very likely the problem.

 

[Jonathan Kay]

Did you find the cause?

Jonathan

[Grandmaster Flatcap]

Hi JK.. Yes, new earth strap and a clean up of the earth point sorted it.

Thanks to for the help & info 

[Jonathan Kay]

Thanks. Well done.

Jonathan