Section V. ORGANIZATIONAL TROUBLESHOOTING
HUPP MF510B, MF510C, MF60A-24V, MF60B-24V
TEST OR INSPECTION
1. HEATER DOES NOT START
Step 1. Check for blocked air inlet or exhaust pipe.
Clear all passages to and from the heaters (refer to applicable vehicle
Step 2. Check for adequate fuel supply.
Troubleshoot vehicle fuel system (refer to applicable vehicle technical
Step 3. Check for proper voltage requirements as follows:
a. Disconnect control box cable to heater.
b. Using multimeter set to read dc voltage, put red probe on terminals of
control box cable and black probe to good ground.
If multimeter reads anything other than 19 volts to 28 volts,
troubleshoot vehicle electrical system (refer to applicable vehicle
Step 4. Check for flooded heater (page 2-19).
Step 5. Remove guard (page 2-31).
Step 6. Check heater as follows:
a. Start heater (page 2-60).
On most vehicles, MF510B, MF510C and MF60B-24V heaters get their intake air
from outside the vehicle. Choke these heaters by going outside the vehicle and
covering the intake elbow.
b. Hold hand over air intake grill for five seconds and then remove for ten
c. Repeat step b for two minutes or until heater starts.
if heater starts, notify Direct Support Maintenance for fuel control
Step 7. Check for defective igniter as follows:
a. Remove igniter (page 2-35).