I
replaced the compressor and it still won't come on
Because
the way the factory Expedition & Navigator compressors are built, they consume
more amps than any other Ford/Lincoln compressor of comparable size and they are
extremely hard on 2 things. One is the armature inside the electric motor part
of the compressor and the other being the power supply, which is the compressor
relay.
When
the armature goes bad, the power consumption can increase and require even more
power from the relay. These relays are a solid state design and don't do a very
good job handling such a large current load and will usually be damaged.
With
that being said, if you have replaced the compressor and it won't run, check for
power at the compressor within 90 seconds of turning on the ignition. (after
90 seconds, the module will time-out and give up)
Don't
worry, you didn't replace the compressor for nothing. You "may have"
temporarily gotten it working again by just replacing the relay, but because the
compressor was actually what started the problem, the new relay would be damaged
in a short time if the compressor hadn't been replaced.
WHERE
IS THE RELAY LOCATED?
