TM 5-4520-256-14
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 7.
Check for zero volts at X2 of K9 Contactor with OFF/VENT/HEAT switch (S1) in vent position.
If voltage is present (indicating open in ground wire) replace wire (para 3-32.1).
If no voltage, proceed to step 8.
Step 8.
Check for 120 (+/-10) Vac at T1 of K9 Contactor with OFF/VENT/HEAT switch (S1) in vent position.
NOTE
Initial voltage will be 88 (+/-2) Vac then increase to 120 (+/-10) Vac after 3 seconds.
If voltage is not 120 (+/-10) Vac (indicating open in K9 Contactor) replace K9 Contactor (Para 3-32.1).
If voltage is correct, proceed to step 9.
Step 9.
Check for 120 (+/-10) Vac at B1 motor with OFF/VENT/HEAT switch (S1) in vent position.
NOTE
Initially voltage will be 88 (+/-2) Vac then increase to 120 (+/-10) Vac after 3 seconds.
If voltage is correct (indicating B1 motor failure), notify Direct Support Maintenance.
13.
HEATER FAILS TO OPERATE.
Check for failure of the R1 rectifier or TT hour meter which shuts down the heater and might also damage the
combustion control relay K8.
Remove filters (para 3-10).
Remove terminal board cover (3, figure 3-42.3) if present (model H83 only).
Loosen top terminal board screws 7 and 9 (refer to figures FO-1 for model H82, and FO-2 for model H83).
Remove wires X36A16N and X15C16V from terminal board.
Tighten top terminal board screws 7 and 9, and install terminal board cover if present.
Change 5 3-16.3
