Possible causes and solutions:
Battery
* Check battery voltage and capacity.
* Clean the battery terminals and tighten them.
* Replace the battery if necessary.
Generator
* Check generator voltage.
* Check the alternator belts.
* Replace the generator if it is faulty.
Wiring
* Check fuses and relays.
* Look for signs of corrosion, damage or exposed wires.
* Repair or replace damaged wiring.
Ignition switch
* Check the contacts in the ignition switch.
* Replace the ignition switch if it is faulty.
Weight
* Check the ground connections between the body, engine and battery.
* Clean and tighten ground connections.
Engine computer
* Check the error codes in the engine computer.
* Reprogram or replace the engine computer if necessary.
Other possible reasons:
* Faulty headlights or lights
* Alarm problems
* Faulty sensors
* Fluid leaks (such as antifreeze or power steering fluid)
Troubleshooting steps:
1. Check the battery.
2. Check the generator.
3. Check fuses and relays.
4. Check wiring.
5. Check the ignition switch.
6. Check ground connections.
7. Check the engine computer.
8. Eliminate other possible causes.
If you are unable to fix the problem yourself, contact a qualified mechanic for help.