I have just had the exact same problem with an 03 ka. After fiddling and looking for lose wires , I replaced the light switch/indicator/wiper control unit on the steering wheel and everything works again. It must be a dodgy switch in the module, but you cant really service/repair them. The replacement cost me £12 on e-bay and was off a Mk 3 Fiesta. The pukker ones for ka's are available but seem a bit more expensive, and they are identical except the height of the hazard light switch.
Kevin Cullen
December 2008
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