TM  10-3930-638-24&P 1. OIL PRESSURE GAGE. indicates engine oil pressure and  is  electrically  connected  to  engine  oil  pressure  sender located on right side of engine. 2. FUEL GAGE. Indicates quantity of fuel in fuel tank; electrically connected to fuel level sender located on top of fuel tank. 3.  ENGINE  OIL  PRESSURE  INDICATOR.  Illuminates indicating low oil pressure; electrically connected to engine oil pressure switch located on right side of engine near fuel filters. Indicator illuminates when switch closes at decreasing pressure of 8 ±2.5 PSI. 4.  ENGINE  WATER  TEMPERATURE  INDICATOR. Illuminates indicating engine is overheated; electrically connected to engine temperature switch located in cylinder head. Indicator illuminates when switch closes at 205 degrees F. 5.  ALTERNATOR  INDICATOR.  Illuminates  indicating battery is not recharging; connected to terminal I of alternator. b. Instrument Panel Switches and Gage Lights. 6. HYDRAULIC  FILTER  INDICATOR.  Illuminates indicating hydraulic filter is clogged and requires replace- ment;  electrically  connected  to  hydraulic  filter  switch located in filter head, Indicator illuminates when switch closes at 20 ±3 PSI increasing pressure. 7.  TRANSMISSION  TEMPERATURE  INDICATOR. Illuminates indicating transmission is overheated; electrically  connected  to  transmission  temperature  switch located in right side of transmission. Indicator illuminates when switch closes at 265 degrees F. NOTE HYDRAULIC  FILTER,  transmission  tempera- ture, and engine temperature indicators will illuminate when ignition switch is placed in LAMP  TEST  position. 1, GAGE LIGHTS. Provide illumination of oil pressure and fuel gages; lamps are contained within these gages and are controlled by VEHICLE LIGHTS switch. 2. VEHICLE LIGHTS SWITCH. Consists of three separate sections: main switch, auxiliary switch, and mechanical lock. Main switch controls application of power to black out tail and stop light, stop light switch, service tail light, and front and rear flood light switches. Auxiliary switch controls application of power to gage lights and brightness of these lights, and power to service tail  lights.  Mechanical  lock  prevents  main  and  auxiliary switches from applying power to lights except black out tail lights. 3. FRONT FLOOD LIGHTS SWITCH. Applies power to  illuminate  front  flood  lights. 4. REAR FLOOD LIGHTS SWITCH. Applies power to  illuminate  rear  flood  lights. 1-10