C15 wassell Lucas led headlight bulb

[rhyatt]

Hi thanks for the readings that you found.
Yes full 12v conversion.
A 6v coil at standby will pull 5 or 6 amps or so , so if the engines not running any bulb will go dim.

My led bulb wasn't going dim but actually switching itself on and off (more off truth be told).

I fitted the new full wave rectifier but the bulb still flickered , so it wasn't my original 12v conversion reg rec.

I'll just use my 10w riding brighter pilot light , I think !!

[DAVE BRADY]

Hi,

There is a 12v 21w or 23w halogen bulb available to fit in place of the pilot bulb.  I think it is made by Bosch. As it is not focused like the main bulb it gives a good light for day time riding and if necessary gives enough light for slower night time riding.

Dave.

[rhyatt]

Thank you, I'll check it out

A quick Internet search found them , but they're all offset pins

[DAVE BRADY]

Hi,

I will see if mine has a number on it but I am sure it is a direct replacement.

Dave.

[Rog1]

I've been looking at the C15 wiring diagram. For reasons I can't work out, there are terminals on the lighting switch connected directly to the alternator. That is, there is alternating current at the switch. Is it possible that your headlamp is being fed by ac?

[V500]

Does the bike have an Emergency Start switch position?

[Rog1]

It does, I think.

[cdsdorset2]

Have you considered giving Ferret the electrical genius a ring?

[JulianS]

The halogen pilot bulb replacement has a BA9 9mm base.

https://www.classicbulbs.co.uk/products/b433-12_volt_20w_mcc_ba9s_halogen_base_miniature_halogen_bulb-b433#pic0

[JulianS]

This is one I bought years ago.

[JulianS]

I recently fitted a Lucas branded P45T headlamp bulb to the Cibie light on my 12 volt dynamo A10. No bulb flickering with the engine running at any rpm.

So is it an alternator/regulator/rectifier issue for the C15 or an issue with the Lucas Wassell bulb? Is it worth asking Wassell or the supplier or worth trying a bulb from different source?

[rhyatt]

Just to answer a couple of comments above.
Firstly thank you.

I have 2 C15s with 12v conversions , going 2 of the 3 lucas alternator wires together and feeding a reg rec etc.

Yes the original loom has E start but this is bypassed in this joint of the 2 wires , as you're using all the alt coils together to give 12v.

The wassell bulb issue is on both bikes and even a change of bulb by the supplier made no difference.

Refresh , bulb is fine when put across a separate battery , nice and bright .
Put it in the bike ign off , nice and fine
Start the bike , flickering on and off.
Earth's all fine etc , all connections soldered etc

I rang wassell and we discussed the problem and I provided meter readings for their tech guy , he was uncertain of the reason.
I'm now using a 36/42 standard bpf incandescent bulb and a 10w pilot to ride by