16-pin Plug on Select Control Board
1. Unplug wiring harness from board.
2. Check for appropriate voltage on connector pins with Select Control Board terminals jumpered. See table
2 for values and example below.
If proper signals are not present, replace the Select Control Board. If signals are present at the board and not the
other end of the wiring harness, the wiring harness is defective.
TROUBLESHOOTING EXAMPLE:
Motor is not running on a call for cooling.
1. After performing checks in Thermostat section, follow steps 1 thru 5 in the Wiring Harness section. Then proceed
with the example.
2. With all thermostat wires removed from the Select Control board, place a jumper wire between R and Y1 low
voltage terminals on the Select Control board.
3. Check table 2 for pin number on the 16-pin connector associated with the Y signal. The correct pin is #6. The far
right column shows that(-) 12VDC should be present between pin #6 and pin #1 (common) on the 16-pin
connector.
4. Set meter to read DC voltage. Place meter between pins #1 and #6 and check for (-) 12VDC (common side of meter
on pin #1.) If signal is present, the problem is the module or motor. If signal is not present, then problem is either
wiring harness or Select Board.
These steps can be repeated for the other modes of operation.
To check Select Control Board:
1. Leave jumper wire in place between R and Y1.
2. Remove 16-pin wiring harness from the Select Control Board.
3. Check table 2 for pin number on the 16-pin connector associated with the Y signal. The correct pin is #6. The far
right column shows that(-) 12VDC should be present between pin #6 and pin #1 (common) on the 16-pin socket
connector.
4. Place meter between pins # 6 and #1 on the socket connector and check for (-) 12VDC.
5. If voltage is present, the wiring harness is bad. If not, the Select control Board is bad.
D. Verify Motor Winding Section:
Before proceeding with module replacement, check the following to ensure motor winding section is functional. With
control module removed and unplugged from the winding section:
1. The resistance between any 2 motor leads should be similar.
2. The resistance between any motor lead and unpainted motor end plate should be greater than 100K ohms.
3. If motor winding section fails one of these test, it is defective and must be replaced.
CARE AND MAINTENANCE
For continuing high performance, and to minimize possible equipment failure, it is essential that periodic maintenance be
performed on this equipment. For a current copy of the detailed Maintenance Program, log on to
www.firstco.com
and look
under Product Information.
WARNING:
Disconnect all power to unit before servicing field wires or removing control package. The
disconnect (when used) does not disconnect power to the line side of the disconnect, but does allow safe
service to all other parts of the unit. If the unit does not have a disconnect, disregard the foregoing. Instead,
make sure that a disconnecting means is within sight from, and is readily accessible from, the unit. Discon-
nect all power to the unit before performing any maintenance or service on it. Failure to follow this
WARNING can cause electrical shock, fire, personal injury or death.
The minimum maintenance requirements for this equipment are as follows:
1. Inspect and clean or replace the air filter every 30 days or more frequently if severe conditions exist. Always replace
the filter with the same type as originally furnished.
2. Inspect cooling coil before each cooling season. The coils must be kept clean, any dust or other contaminants which
accumulate on the heat transfer surfaces interferes with the air flow and impairs heat transfer. The coil can be
cleaned by one of the following methods: Cleaning with low pressure compressed air or flushing and rinsing with
water and a detergent is advisable for greasy surfaces.
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