Rear Indicator Stopped Working

[markbradley]

Hi,

My rear right indicator has stopped working, I replaced the bulb and cleaned the connection and it still won't flash.

From what I read in my Haynes manual, it's not the fuse or relay because all the other lights are working fine. Is that right? So I'm guessing it's a faulty connection or broken wire, I can't see any obvious faults looking at either end.

Any suggestions where the problem might be?

Cheers!

[kevtherev]

Start with isolating the fault
Measure at the + bulb holder for 12v.
Then work your way back.

[markbradley]

Hi Kev,

I am getting a small voltage, but not as much as the left indicator, which works fine. Does the wire run from the left to right indicator in RHD models? That might explain why only one indicators working.

Cheers!

[kevtherev]

When you check the bulb holder for +ve, try earthing the probe on the chassis
Reads like an earth fault to me
The live right, is a separate circuit to the live left.

[markbradley]

OK will give it a go!

Cheers!

[markbradley]

Doesn't see to be an earth fault. I've taken everything apart and cleaned all the contacts (under steering column, at the fuse box and at the back end) with sandpaper and contact cleaner, still no joy! Not sure where to go from here.

[kevtherev]

Ok do you have 12v at the connector to the light box (not the bulb holder)

[markbradley]

Yes, think I've managed to locate the problem. I'm pretty sure it's where the indicators split because my multimeter is reading voltage everywhere else. Although I didn't manage to find where the two indicators join. I'm hoping someone will be able to tell me where it is.

Cheers!

[kevtherev]

They don't join.
They are separate circuits, otherwise when you turn the indicator on they would all flash.

[Smiffo]

Like Kev says - surely they must be separate?

On a side note, I would imagine testing for voltage at the indicator would be difficult, as the voltage would be fluctuating between states of trying to illuminate the bulb, and allow it to turn off again. I imagine that would be an issue for any multimeter - especially a digital one - and may show as a low voltage..... You would need a continuous voltage to be sure, and know that your earth point is good ( don't use the bulb earth bit, or you aren't eliminating anything. )

Make sure the earth is good first. Measure resistance between the earth aspect of the bulb fitting, and a clean bit of the chassis. If that is good, then you know it is an issue with the live feed.