54
Code
Fault
Diagnosis Step
Remedy
None
Open FC1 and/
or FC2 Fuses.
1. Verify that 120VAC
Voltage Selector Plug
is not installed with a
240VAC fi eld power
supply.
Check that proper Voltage Selector Plug is installed. If OK,
proceed to step 2.
If 120VAC plug is installed and fi eld supply voltage is
240VAC, FC1 and FC2 fuses will have to be opened. Install
the correct Voltage Selector Plug and new FC1 and FC2 fuses.
2. Check for faulty
Transformer wiring.
Inspect Transformer wiring. Ensure insulation on wiring is not
worn. If OK, proceed to step 3.
3. Defective Transformer
Replace Transformer.
Open FC3 and/
or F1 Fuses
1. Check for faulty Gas
Valve wiring.
Inspect Gas Valve wiring. Ensure insulation on wiring is not
worn. If OK, proceed to step 2.
2. Verify that Gas Valve is
not defective.
Mesure for resistance across Gas Valve terminals and between
each terminal and ground. If short exists, replace Gas Valve.
If OK, proceed to step 3.
3. Check for faulty
Control Module wiring.
Inspect Control Module wiring. Ensure insulation on wiring is
not worn. If OK proceed to step 4.
4. Control Module is
defective.
Replace Control Module.
Open FC4
Fuse.
1. Check for faulty Igniter
wiring.
Inspect Igniter wiring. Ensure insulation on wiring is not
worn. If OK, proceed to step 2.
2. Check for faulty
Blower wiring.
Inspect Blower wiring. Ensure insulation on wiring is not
worn. If OK, proceed to step 3.
3. Check for defective
Igniter.
Disconnect Igniter plug from Control Module. Measure
resistance across Igniter. Resistance should be 10.9-19.7 ohms
at at 77°F. If out of this range, replace igniter. If OK, proceed
to step 4
4. Check for defective
Blower.
Disconnect Blower plug from Control Module. Measure
resistance across Blower windings. Winding resistance across
lead should be in the fo
llowing range: Red-to-White: 4 to
5 ohms. If measured values vary substantially from these
values, blower is defective. Replace. Otherwise pr
oceed to
step 5.
5. Control Module is
defective.
Replace Control Module.
Figure 28:
TROUBLESHOOTING