Table 4-1. TROUBLESHOOTING (cont.)

TM 5-4120-359-14

Table 4-1. TROUBLESHOOTING (cont.)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Step 4.

Check compressor motor B1 windings.

(a) Remove power.

(b) Measure resistance between connector J10 pins:

A and B

A and C

B and C

If not, replace compressor.

TEMPERATURE CONTROL NOT EFFECTIVE

Step 1.

Check temperature control A1. (See paragraph 4-47.)

Replace if found bad.

Step 2.

Check temperature sensing probe A1-RT. (See paragraph 4-20.)

Replace if found bad.

Step 3.

Check mode selector switch. (See paragraph 4-103.)

Replace if found bad.

Step 4.

Check wiring using wiring diagram figure 4-3.

Replace or repair as indicated.

UNUSUAL NOISE OR VIBRATION

Step 1.

Examine air conditioner shock mounts and attaching hardware. Are shock mounts undamaged and

firmly attached? Is air conditioner properly alined with shelter adapter duct?

(1) Remove power.

(2) Assure there is no contact between the air conditioner and metal portion of shelter adapter

duct.

(3) Tighten loose screws.

(4) Install missing screws.

(5) Change defective shock mounts.

(6) Apply power.

Step 2.

Examine fresh air duct, all covers, and attaching hardware. Are air ducts and covers undamaged and

firmly attached to housing?

(1) Tighten loose screws.

(2) Install missing screws.

(3) Repair or change defective ducts and covers.

(4) Apply power.

Step 3.

Check evaporator section.

(a) Remove power.

(b) Remove top cover, evaporator.

(d) Check blower impellers for interference or being out of round.

(e) Are parts firmly attached? Do impellers spin freely without wobble?

(1) Tighten loose screws.

(2) Install missing screws, clamps, and brackets.

(3) Adjust position of impellers until they spin freely.

4-13