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Q: My Suzuki GSX-R1100G runs and starts perfectly after the fitting of a new starter motor. With engine warmed to running temperature, the engine is than revved to 5000rpm and the battery is charging to 14.54v (this to check alternator charging, minimum is 13.50v.) But when at tickover and the main headlight switched on the engine dies. Turn the lights off and it restarts first press and it quite happily ticks over, select the main headlights again and it dies! A: That does sound strange. The alternator and charging system seem to be okay. One explanation would be that the headlamps draw so much power that the extra drag caused by the alternator stalls the engine: hardly likely. So it must be a short circuit, depriving the ignition system of power – but the headlamps and ignition are fed by separate fuses, neither of which blows as the bike seems to work okay afterwards, unless your bike’s wiring has been modified of course. I think you are going to have to get hold of a copy of the wiring diagram and work your way through with a series of logical tests. You can try a number of things: firstly do the headlamps work okay, despite the engine stopping? You might try taking one or both headlamp bulbs out, or taking fuses out one by one, etc to isolate the cause.