Diagnosis and repair of the heater ZIL-5301

Decrease of the indicator line on the status diagram of the indicator shows the state of its extinction (for the PZhD8 heater)

If problems occur, the following recommendations should be followed to correct them.

heater connection diagram

Fig. 1. PZhD-12A heater connection diagram: 1 - control unit; 2 - plug-in terminal to the cabin heater fan speed controller; 3 - timer-thermostat; 4 - thermal fuse 291.3722 for 30 A; 5 - thermal fuse 29.3722 for 20 A; 6 - block of thermobimetallic fuses 13.3722-01 for 7.5 A x 2; 7 - thermal fuse 292.3722 for 10 A; 8 and 9 - numbering of contacts in the heater blocks; 10 - plug blocks; 11 - numbering of contacts in the timer-thermostat block; 12 - numbering of contacts in the pads of the control unit; 13 - output to the mass switch; 14 - liquid electric pump 351.3730; 15 - candle 25.1830.01.0100; 16 - air blower 20.1673991500; 17 - additional resistor P75.638.000; 18 - thermal fuse 19.3722; 19 - electromagnetic fuel pump 2.71106010; 20 - temperature sensor 40521S; 21 - flame indicator IYuK7'468332.003; 22 - heater. Wire colors: white - 158, 158 a; 172; blue - 166; yellow - 160, 160 a; green - 161, 161 a; red - 170, 170 a; 173; brown - 159, 159 a, 159 b, 159 g, 159 d; 159 e; 159 in; 159 w; orange - 169, 171, 171 a; orange-black -163; pink - 165, 165 a, 169 a; blue - 156, 156 a; gray - 157, 157 a; purple - 162, 162 b; black - 168.

If the air blower malfunctions, disconnect the air blower wire connector, unscrew the nut securing the thermal fuse cover and remove the cover; unscrew the screw of the clamping collar of the air blower, part the halves of the clamp and remove the blower.

Assembly must be done in reverse order.

If the additional resistor malfunctions, it is necessary to disconnect the wires from the terminals of the additional resistor, unscrew the M5 screws, remove the wire connecting the elements of the automation system to ground, and dismantle the additional resistor from the air inlet.

Assemble in reverse order.

If the glow plug malfunctions, use the S=8 wrench to unscrew the wire fastening nut, remove the spring and flat washers, the current lead, the pressure washer, the insulating washer.

Remove the ground wire and unscrew the glow plug using the S=19 wrench.

Assemble in reverse order.

If the flame indicator malfunctions, disconnect the wire connectors, unscrew the two screws, remove the cover, gasket and flame indicator with housing and gasket.

Assemble in reverse order.

If the temperature sensor malfunctions, disconnect the sensor wire connector with the S=19 key and unscrew the sensor.

Assemble in reverse order.

If the thermal fuse is faulty, unscrew the nut securing the thermal fuse cover and remove the cover, remove the wires from the thermal fuse terminals and unscrew it.

Assemble in reverse order.

If the fuel pump malfunctions, disconnect the solenoid wire, loosen the fuel pipe clamps and remove them.

Remove the two screws securing the fuel pump, disconnect the ground wire and remove the fuel pump. Reassemble in reverse order.