MEMO ENGINE PREHEATING SYSTEM An air heater (8) is installed in the intake manifold of the engine. When the starter switch (5) is turned " PREHEAT " the current flows from the battery (1) fusible link (3) "B" terminal of starter switch (5) " R1 " terminal of starter switch (5) "C" terminal of preheat relay (7) battery (1). This current flow causes the coil in preheat relay (7) to be activated, closing contact. When the contacts of the preheat relay (7) are closed, the heating coils of the air heating device are heated by current flowing from the battery (1) battery relay (2) preheat relay (7) air heater (8) ground. The duration of the heating time is approximately 20 seconds.
After 20 seconds later to start preheating, the preheat indicator light will turn "OFF" by the timer in the e-EPOS controller. If the starter switch (5) turns "START", the heating process will be going on because the current flows into the coil in preheat relay (7) through "R2" terminal of starter switch (5).
3 6 9 4 CN6-1,2 ACC 5 C 2 A PREHEAT CN7-4,5,6 L5 R2 B R1 BR 10 CN2-13 CN4-4,5,6 CN2-1 - + - + 11 1 C B 200A - 7 8 STARTER SWITCH CONNECTION D H + FG002088 Figure 5 ENGINE PREHEAT CIRCUIT SP001727 Electrical System Page 16 BR PST TML B BR R1 R2 C ACC OFF ON START Reference Number Description 1 Battery 2 Battery Relay 3 Fusible Link 4 Circuit Breaker 5 Starter Switch 6 Fuse Box Reference Number Description 7 Preheat Relay 8 Air Heater 9 Preheat Indicator Light 10 Diode 11 e-EPOS Controller