11
CONDITION C
GC-4A LIGHT OFF, RED LIGHT ON
Turn Rocker Switch OFF and ON. If, within 10 seconds, the GC-4A light come ON, proceed to CONDITION “E”.
If after the toggle switch is turned “OFF” and “ON”:
- GC-4A light remains “OFF”.
- Red light is “ON” but there is no “Prepurge Cycle” or blower operation initiated (unit is in standby mode).
- Green light “ON” immediately - but no gas flows to unit. The ignition module has lost ground continuity
between the module and ground. Replace terminal connection on the end of ground wire (green)
leaving the module.
If GC-4A light remains OFF, proceed with this check.
POSSIBLE CAUSE
VERIFICATION
SOLUTION
Wiring
Check if green ground wire from
If screw is loose, secure screw. If
GC-4A is securely fastened to the
wires are not on a common screw
ground screw. Also check
rewire the grounds.
transformer ground.
If GC-4A light remains OFF, proceed
with check.
GC-4A Ignition Control
Turn Rocker Switch OFF.
If 24V, reattach connector to GC-4A.
Remove 6-pin Molex connector from
If GC-4A light remains OFF after 10
GC-4A. Turn Rocker Switch ON.
seconds replace GC-4A.
With a voltmeter, check for 24V from
pin 2 (brown wire) on connector to
If no 24V, check wiring and
ground.
connectors until 24V is established.
