Figure 2-31. Combination rear light. exploded view.

(2) Disassembly.

b. Combination Rear Lamp.

(a) Pull the rubber bezel (7) from the base (5).

(1) Removal. Refer to figure 2-31 and remove as

(b) Loosen the terminal screws and disconnect

follows :

the wires from the lamp.

(a) Unplug the wires at the connectors.

(b) Remove the nuts and washers securing the

bezel.

light (1) to its mounting bracket and remove the light.

(3) Lamp replacement. The lamp can be replaced

with the light installed on the truck. Refer to (2) above.

Figure 2-31. Combination rear light. exploded view.

(2) Disassembly.

(a) Connect a voltmeter between the horn

(a) Remove the lens retainer (2).

terminal and ground and press the horn button.

(b) Remove the lens (3).

Observe the voltage reading on the voltmeter.

(b) If the voltage is between 0- and 10.7-volts,

and twisting counterclockwise.

check for an open circuit, defective horn relay, poor

(3) Bulb replacement. The bulk can be replaced

wiring, or a shorted horn roil.

with the light installed on the truck. Refer to (2) above.

(2) If the horn signal is weak and the voltage at

the horn terminal is normal, attempt to increase volume

2-40. Horn and Horn Relay

with the volume adjusting screw in the horn cover.

a. General. The horn and horn relay are located

Turn the screw in to increase volume : out to decrease

volume.

under the toe plate on the right-hand side. Pressing

(3) If a defective horn relay is indicated: check

the horn button actuates the horn relay. The horn

for proper airgap, point opening, and closing voltage

relay, when actuated, closes the battery-to-horn

before replacing the relay. Correct settings are as

circuit. Use of the relay permits a shorter, more direct

follows :

connection between the battery and horn. This results

(a) Air gap (with points closed)- 0.020 inch.

in higher voltage at the horn and avoids pulling full

(b) Point opening -0.018 inch.

current through the horn button.

h. Test and Adjustments. In event of horn mal-

c. Removal. Refer to figure 2-32 and remove the

function, always check to be sure that the battery is

horn and horn relay as follows:

producing full rated voltage before conducting the

(1) Remove the toe plate.

following tests.

(2) Disconnect all wires at the horn and the

(1) If the horn produces a weak signal, proceed

horn relay.

as follows :

2-38