TM 9-4120-403-14
5-29. SOLENOID VALVES (L1 AND L2) COIL REPLACEMENT
This task covers:
a. Test
b. Replacement
INITIAL SETUP
Tools
General Safety Instructions
Tool Kit, Refrigeration
WARNING
Power Supply
Voltages used can kill. Always disconnect power cord
to air conditioner before performing any internal main-
Equipment Conditions;
tenance. Shutting unit off at its control panel does not
Top Panel Removed (For access to L2 only)
disconnect unit power.
Do not attempt any disassembly of solenoid valve other
than coil removal with a refrigerant charge in the
system. Refrigerant will be sprayed out dangerously if
screws that attach tube and plunger assembly to valve
body are loosened.
Test
NOTE
The following basic instructions apply to both the equalizing solenoid (L2) and the liquid line solenoid (L1).
(1) Using a multimeter set on lowest OHMS scale, check for continuity between contacts I and M on connector
P4 (L1) and contacts H and g on connector P4 (L2). If continuity is not found, coil is open and must be replaced.
(2) Using a multimeter to check for continuity between contacts H, I, M, and g in connector P4 and coil casing. If
continuity is found between any contact and the casing, the coil is grounded and should be replaced.
(3) If continuity checks are satisfactory, apply 28 volts dc from an external power source across contacts IandM
on connector P4 (L1) orH and g on connectorP4 (L2). Listen for a sharp click when valve changes position. If click is not
heard, internal valve problems are indicated and entire valve should be replaced. (Go to para 5-30.)
5-92