THERMOSTATIC SWITCHES (S2 and S3)

TM 5-4120-359-14

4-29. THERMOSTATIC SWITCHES (S2 and S3)

Preliminary Procedure: 1. Disconnect power.

2. Remove top evaporator cover. (See paragraph 3-21.)

WARNING

Disconnect input power from the air conditioner before performing maintenance

on any part of the electrical system. The voltages used can be lethal.

a. Test

NOTE

Test switch when the temperature is below 100F (38C).

(1) Tag leads, using screwdriver, remove four screws that hold leads to switch. (There are two switches.)

Figure 4-25. Thermostatic Switch Test (Model DHF)

(2) Test for continuity between switch terminals 1 and 2 and between 3 and 4.

If none, switch should be

replaced.

NOTE

Switch contacts should open at 145-155F (63-68 C) and close when temperature

drops to 100-120F (38-49C).

4-68 Change 2