This index lists all relays referenced in the
Find the relay index on sheet 2 of the hull
designation, relay designation, function (the component it
controls), symbols, and the sheet number(s) where you find the
Relay designation. This index also uses an alpha-numeric
code to identify the relays. The diagrams use the letter
A to indicate the relay mounts on a printed circuit board;
the number following the A shows what number the diagram
has designated the relay on the circuit board (e.g., A1K3,
The letter K indicates a relay mount on an
electrical assembly, and the number following the letter
indicates the number of the relay in the component (e.g.,
For example, if a relay has the designation A1K5, you know
it mounts on printed circuit board number 1 and is the
fifth relay on the circuit board.
If the relay has the
designation K2, you know that it is the second relay in a
In both examples, you could use the assembly
designation code to find the assembly on which the relay
or printed circuit board mounts.
This index identifies the relay winding
terminals and contacts by letter and number, or number
It also shows the number of windings and contacts
the relay has and their normal position, normally open
(N.O.) or normally closed (N.C.).
Look at the relay index in the extract (appendix A) and
find the relay designated K3 with the function of
controlling the rear fuel pumps. Examine the symbols for
this relay. After you have examined the symbols, you know
this relay uses X1 and X2 as the connections for its relay
winding terminals (on sheet 7) and has four normally open
contacts (one on sheet 7 and three on sheet 13).
Look at the relay index again and find the relay
designated A1K3 with the function of controlling the fire
extinguisher first shot discharge.
Examine the symbols
for this relay. After you have examined the symbols, you
find this relay has two winding that use 9 and 2, and 4
and 7 as the connections for winding terminals (on sheet
25) and has one N.O. contact (on sheet 16).