HUPP MF510B, MF510C, MF60A-24V, MF60B-24V - CONTINUED
TEST OR INSPECTION
4. HEATER OUTPUT TOO LOW-CONTINUED
Step 3. Check for defective HI/LO pressure regulator in fuel regulator valve (1) as follows:
Disconnect HI/LO pressure regulator lead (5) from terminal 4 of terminal strip
Place red multimeter probe on HI/LO pressure regulator lead (5) and black
probe on ground.
If multimeter reading is less than 70 ohms or greater than 110 ohms, re-
place fuel regulator valve (page 3-47).
Step 4. Check for defective HI/LO fire relay (6) as follows:
Set multimeter for dc voltage measurements.
Start heater (page 2-60).
Place red multimeter probe on terminal 4 of terminal strip (4) and black probe
d. Switch heater back and forth between HI and LO operation.
If multimeter reading does not change back and forth between zero volts
supply voltage value, replace HI/LO fire relay (page 3-30).