Auto Electrical Works Paper 2, May/June 2015

Question 2

Fig. 1 is a typical starting system.


  1.  Identify the parts labeled;
  2. (i)P (ii)Q (iii)R (iv)S (v)T (vi)U
  3.  List three methods of determining battery terminals.
  4.  State the function of the following in a starting system;
  5. (i)Ignition switch; (ii)Starter motor; (iii)Starter relay.


       The expected answers were;

  1. Parts of a starting system
  2. (i) P; battery (ii)Q; fuse (iii)R; ignition switch (iv)S; starter relay (v)T; starter motor (vi)U; earth
  3. Methods of differentiating battery terminals
  4. (i)Size (big; positive, small; negative) (ii)Colour (red; positive, blue/black; negative) (iii)Signs (+; positive, - ; negative)
  5.  Function of starting system parts
  • Ignition switch; permits operator to control starting system operation
  • Starter motor; used for cranking the engine. Converts electrical energy to mechanical energy to turn the crankshaft
  • Starter relay; direct a large electric current to the starter motor which in turn sets the engine in motion.                                                                             
  • The candidates were required to identify six parts of starting system, list three methods of differentiating battery terminals and state the function of three components of a starting system; ignition switch, starter motor, starter relay.

    The performance was reported to be below average.