[Svxswede]

Say that you have a single lightbulb connected to the battery. Over the battery poles is the alternator. A 100 W bulb will draw 100/12 =8 amps, and the resistance of the bulb is 12/8 =1,5 ohms.

By applying Ohms law, increasing the voltage also increases the amperage.

There is of course a limit to the powersource ability to put out amperage, a car alternator can put out 100 amps up to quite high voltage levels.

Lets say the alt produced 20 volts instead, the battery will act as a buffer for a while but at a level overvoltage reaches the system and if the resistance of a circuit is 10 ohms and normally consuming 1,2 amps it will now draw almost the double.

Any relay will have to handle twice amps and also the fusible link which handels many powerconsumers will be overloaded.

Still havent found the fault at fuse 15.....

Seems a lot of circuits are involved there.

Alex