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Scheduled maintenance service
Follow Normal Maintenance Schedule if the vehicle is usually operated where none
of the following conditions apply.
If any of the following conditions apply, follow Maintenance Under Severe Usage
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Bulb wattage
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Check spark plugs and ignition system
Inspect your spark plugs as described in section 7 and replace them if necessary.
Also check all ignition wiring and components to be sure they are not cracked, worn
or damaged in any way. ...