Test. Test by disconnecting one lead from each
resistor. With an ohmmeter, check each
resistor for 7.5 ohms 0.5 percent.
Replacement. Remove resistors by unsoldering
leads and removing from clips.
5-6. ANNUNCIATOR CONTROL ASSEMBLY TB6 (76,
figure 5-1). The annunciator control relay assembly
contains four terminal boards, 20 diodes, and 13 relays:
High Oil Temperature
Low Oil Pressure
Low Fuel Level
Check each relay using test circuits shown in
figure 5-16. Energize each set of relay
contacts individually by applying 24V DC
directly to leads. Check for open or closed
contacts (no continuity or continuity) as
indicated in figure 5-16. Check that each set
of contacts revert (to either closed or open
position) when deenergized. If only relay fails
to either open or close as indicated, it is
defective and must be replaced.
Check diodes for polarity. A good diode will
read high resistance one way and low
resistance the other way. A defective diode
will read full scale both ways, or will read
infinity (no reading) in either direction.
Check terminal boards and printed circuit
wiring by repeating steps (1) and (2), but apply
24V DC to TB6 terminals.
Repair. If any of the relays or diodes are
defective, Annunciator Control Relay Assembly
TB6 is repairable by replacing the defective
Figure 5-15. Control Relay Assembly TB10, Test Setup