Post by
C-Kwik »
https://forums.nicoclub.com/c-kwik-u426.html
Tue May 03, 2011 1:26 am
With most electrical issues, the key is to methodically test to rule out problems until you find the problem. While the two issues might be related, I would start out assuming its not until you test every other possibility first. I would also start with the starting system as it is more accessible and a much simpler circuit. I doubt the ignition switch is drawing enough power to prevent the car from starting btw. With that kind of amperage, you'ld likely have a blown fuse. Your battery may be low. IIRC, most of my batteries are usually at something like 12.10V. Not a big difference, but perhaps coupled to a smaller battery, the voltage drop is more severe. What is it physically doing when it fails to crank? Perhaps try hooking up the bigger battery and see if there is a difference. Try swapping the starter relay with another component that uses the same relay to rule that out.
Once you resolve the starting issue or rule out all possibilities, then move onto the lighting issue. Unless there are some wires between the two systems shorting, I doubt they are related. You may need access to the FSM so you can follow the troubleshooting workflow (recommended for both issues if you're uncertain about how to proceed). Generally, when you follow the workflow it will become clear what needs to be fixed.
Lastly, I'd check the power draw with a multi-meter. If its higher than it should be, then you will need to find that. But if it has normal readings, its likely that your battery is too small for the application. Smaller batteries have less Watt-Hours (energy). For a given amount of energy used by the car, the voltage will drop more in a smaller battery than with a bigger battery. For a given amount of current, less voltage means less power is provided (Power = Volts x Current).