Carrier VECTOR 6500 Operation & Service Manual page 190

Alarm
Steps
NO.
92 CHECK 1HTCON2 RELAY COIL
•
TRIGGER–ON: Heater contactor 2 (1HTCON2) circuit is shorted. (The contactor output from the
microprocessor (4MP14) is negative, so the circuit will not be shorted to ground, but is shorted
either within the contactor coil itself, or to a positive wire.)
•
UNIT CONTROL: Engine and Standby Operation: alarm only.
•
RESET CONDITION: Auto Reset or alarm may be manually reset via keypad or by turning the unit
off, then back on again.
NOTE: Follow the steps below until a problem is found. Once a repair or correction has been made, the active
alarm should clear itself (see reset condition above). Operate the unit through the appropriate modes to see if
any active alarm occurs. Continue with the steps below as necessary.
1 Check 1HTCON2
a. Inspect heater contactor coil and
terminals
b. Check contactor coil resistance
c. Check amp draw of coil.
2 Check 1HTCON2 Current Draw
Use Component Test Mode to test
actual current draw of the circuit.
(Refer to Section 5.2.2.)
3 Check 1HTCON2 Wiring
Inspect harness & control box con-
nector pins & terminals. (See wiring
schematic Section 10.)
Alarm/Cause
7−57
Corrective Action
No damage to coil
No damage or corrosion.
Refer to Section 2.12 for correct electrical values.
Cannot be opened (infinite ohms), shorted (Zero
Ohms) or shorted to ground.
Refer to Section 2.12 for correct electrical values.
Use ammeter.
Refer to Section 2.12 for correct electrical values
View current draw in Data List.
No physical damage to harness.
No damage, moisture, or corrosion in connectors.
62-11389