Hella lights/ auto switch problem


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Jul 10, 2007
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Just put new bulbs into my Hella auxiliary lights yesterday, switched them on, all good.
Riding to work this morning and they won't come on, even though my autoswicth's LED is lit up green


Obviously I'll check connections to bulb and the bulbs themselves, but even if they've blown I still have a problem.

Will do some investigation when I get home tonight but anyone had a similar problem that might be able to tell me where to start?

Any know issues with autoswitches?
Approach the problem logically.

First check the quick and simple things like the fuse.

If that is ok, check the earth connection is good.

Beyond that you will need a multimeter and know how to use it to check if you have got power getting to the relay.
Thanks folks.

Have checked the wiring to the bulb and the bulbs themselves, all seem fine.

Over the weekend I'll check the fuse and connection under the tank, but not being electronically minded have no idea how to check the earthing or use a multimeter.

Seems odd that it happened right after I replaced both bulbs, so am sure it's something I've done!

Grrrrr.. I hate electrical faults.
Bulbs are ok, Fuse is ok, connections all seem ok -what now?

I've no idea how to use a multimeter, so a trip to the garage maybe?
You're going to be a bit limited in how much further you can go without a multimeter.

When you say bulb and fuse are ok, presumably this is just a visual check - which can be misleading.

Try testing each bulb directly across the battery with a couple of short lenghts of wire. If they come on you can definately say they work.

Next do the same thing but add the fuse into the circuit. Again if the bulbs light then the fuse is ok.

Next thing to check would be the relay - you should be able to hear it click over when the autoswitch is operated.

Beyond that you need a multimeter.

When you changed the bulbs did you put the same wattage bulbs in as you took out. If the ones you put in were a higher wattage and draw more current than the old ones you may well have blown a fuse.

Are you sure you've located all the fuses. If the auxilliary lights are wired off a fused live with an additional in line fuse having been put in you will need to check both fuses.

Good luck.

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