Battery

• Battery connection in reverse polarity is strictly prohibited. Such a wrong connection will damage the components of the fi system instantly when reverse power is applied.

• Removing any battery terminal of a running engine is strictly prohibited. The moment such removal is made, damaging counter electromotive force will be applied to the electronic unit which may result in serious damage.

• Before measuring voltage at each terminal, check to make sure that battery voltage is 11 v or higher.

  Terminal voltage check with a low battery voltage will lead to erroneous diagnosis.

• Never connect any tester (voltmeter, ohmmeter, or whatever) to the electronic unit when its coupler is disconnected. Otherwise, damage to electronic unit may result.
• Never connect an ohmmeter to the electronic unit with its coupler connected. If attempted, damage to ecm or sensors may result.
• Be sure to use a specified voltmeter/ohmmeter.

  Otherwise, accurate measurements may not be obtained and personal injury may result.

While there are various methods for electrical circuit inspection, described here is a general method to check for open and short circuit using an ohmmeter and a voltmeter.