Imagine you spent yesterday 'on a stage' for 16 hours, not getting into the Bivouac until 2am - cold, exhausted, and feeling queazy after inhaling gallons of CO... but hey, you completed the stage, right?
Then the next day you're out in the desert, when your HID fails... it's getting dark, but every time you rev the engine your HID light cuts out... the tell-tale on the dash is still illuminated so there must be power to the relay, but every time you switch the HID off and back on again, and rev the engine, the light cuts out...
Fortunately you stop at an oasis, and there, under the trees is a Tenere XT660Z - in full rally spec (what are the chances of that then?!) - so you remove your whole HID lamp, ballast and loom from your WR and connect it to the Tenere, which someone had the forethought to leave the key in, and the battery fully charged...
And presto - your HID works absolutely fine, you rev the Tenere lump to the stratosphere and no problems at all, whilet he Tenere stator/battery combo is kicking out a healthy 14.5 volts... hmmmm, you think - maybe the little battery in your WR is not man enough to drive this big chunky ballast after all?
So you ride on a little way, and find someone has left a brand new, bog stock WR450F in a little Bedouin tent (thank you Yamaha UK x)... so again, you hook up your 'portable' lamp/ballast/loom combo to the stock bike, start the bike, switch on the HID, rev the engine, and blow me if it doesn't work perfectly too, albeit the stock stator is only putting out around 12.8-13V... (erm, so maybe I didn't need that new stator after all?!)
So you walk back to your rally bike, with your lamp/ballast/loom combo - reconnect the loom to the battery, and give it another go... and bloody hell it works... rev the engine, still works... it doesn't cut out every time you switch it on, it just works... the uprated stator is kicking out a decent 13.5v too - nice.
So you look at the dash of your rally bike and think what is different... the only thing not in the circuit is the tell-tale lamp which is still fitted into the alloy panel...
You prize out the tell-tale, connect it to the switch on your loom, and...
The bloody light cuts out.
You take the tell-tale out of the loop, switch on the HID, and everything works perfectly.
You fit the tell-tale again, just to make sure... the light cuts out.
You take the tell-tale and smash it with a hammer.
You feel much better now.