TM 9-2320-361-34 17-19. ENGINE COOLANT HEATER TESTING (Contd) 1. 2. 3. 4. 5. 6. 7. 8. 9. KEY TO TEST EQUIPMENT ARRANGEMENT Electric fuel pump 10. Coolant inlet hose Fuel tubing 11. Power source lead Fuel filter 12. 24-volt DC power source Fuel flowmeter 13. Multimeter Fuel shutoff valve 14. Coolant heater assembly Coolant outlet hose 15. Wiring harness Thermometer 16. Control box Coolant container 17. Fuel tank Coolant shutoff valve 17-49