color of the relay is usually black with a brown
base. The wires coming from it are usually seven.
It's above the hood latch release to the right
and very high up. Removing it requires removing
several parts surrounding it.
relay is made up of two relays, one for the fuel
injection system and one for the fuel pump. The
relay sits on a PC board inside a plastic case,
The PCB board contains resistors and some diodes.
The common heat build up is the fuel pump relay,
which causes an expansion and contraction of the
solder joints thus creating an enviroment for
drying and cracking.
Usually the fuel injection system relay may be
the second to fail. If the fuel injection relay
fails, a "check engine light" will
signal a warning and a code may be sought. The
code should point to a fuel injector problem.
have been reported cases of 88-91 Civics where no
sparks have been found due to a bad main relay.
It is possible that the ECU plays a part in the
ignition system but this is not possible after
examining the Civic's wiring diagram. On years 1992 and up, the ECU
manages the sparks. A bad relay usually produce
no spark on these models.