SOLENOID VALVE (COIL REMOVAL).-Continued

TM5-4120-383-14

4-38.

SOLENOID VALVE (COIL REMOVAL).-Continued

Disconnect input power from the air conditioner before

performing maintenance on any part of the electrical

The voltages used can be lethal.

system.

NOTE

The following basic instructions apply to both the

by-pass solenoid L1 and the pressure equalizer

solenoid L2.

Test.

(1) Disconnect power at power source.

(2) Remove fabric cover (para 4-10) and top rear cover (para

(3) Disconnect the solenoid valve connector plug. P8 for L1

solenoid and P9 for L2 solenoid.

(4) Use continuity tester or multimeter set on lowest OHMS

scale to check for continuity between pins A and B in each

connector plug.

If continuity is not found, the coil is open and

must be replaced.

(5) Check for continuity between each pin in connector plug

If continuity is found the coil is grounded and

and coil casing.

should be replaced.

(6) If continuity checks are satisfactory apply 24 volts dc

from an external power supply across pins A and B in connector

Listen for a sharp click when the valve changes position.

plug.

If a click is not heard, internal valve problems are indicated and

Refer to direct support

the entire valve should be replaced.

maintenance.

b. Repair.

The only authorized repair to solenoid valve is

coil replacement.

The coil can be replaced without opening the

refrigeration pressure system.

Do not attempt any disassembly of the solenoid valve

other than coil removal with a refrigerant charge in

the system. Refrigerant will be sprayed out

dangerously if the screws that attach the tube and

plunger assembly to the valve body are loosened.

4-106