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Aircon Interconnect Communication Wire

The interconnect communication wire carries signals between the indoor and outdoor units. If that path is loose, damaged, or unstable, the system may not start or may run abnormally.

What This Part Does

The indoor and outdoor units must exchange control signals. The interconnect communication wire carries that signal path.

This wire path works together with terminal connections and both PCBs. A problem anywhere in the path can stop normal operation.

If the communication wire is damaged or unstable, commands may not pass correctly between units.

How You Would Notice

The unit may not start, may stop unexpectedly, or may show unusual flashing-light patterns. Indoor and outdoor behavior may not match.

Some faults are on and off. The unit may work at one time and fail later without a clear cooling load change.

Users often describe it as the indoor unit responding but the outdoor unit not following.

  • Indoor and outdoor units not responding together
  • No-start or unstable start with signal-like symptoms
  • Flashing-light or error-like pattern

It Might Not Be The Interconnect Communication Wire

Indoor or outdoor PCB faults can create the same symptom pattern because the signal path starts and ends at those boards.

Loose or burnt terminal connections can also interrupt the path without wire damage in the cable run.

We check wire path, terminals, and PCB behavior together before naming the failed part.

How We Check

We inspect the terminal points and wire condition first. We look for looseness, damage, and signs of heat.

Then we compare the indoor and outdoor response pattern to see if signals are passing through the path.

If the wire path looks normal, we continue with PCB checks because board faults can mimic communication-wire faults.

We recommend wire repair or replacement only when the communication path fault is confirmed in the cable or its immediate terminations.

What We Find And What Happens Next

Communication-path cases usually narrow down to terminal fault, wire damage, PCB fault, or no signal-path fault found.

What We Find And What Happens Next summary table
FindingNext Step
Terminal issue in signal pathRepair terminal connection and retest
Communication wire damagedRepair or replace wire path and retest
Wire path normal, PCB fault patternCheck indoor or outdoor PCB
No communication fault foundContinue diagnosis on other startup causes

About The Repair

Communication-wire repair depends on where the damage sits and how accessible the cable route is.

The repair only helps if the true fault is in the wire path. PCB faults need a different repair path.

We confirm the signal path before recommending cable replacement.

After Replacement

The indoor and outdoor units should respond together again if the communication wire was the main fault.

If the mismatch remains, the control boards or another control-path part may still be at fault.

We retest startup and command response before closing the job.

When We Tell You To Wait

If the issue happened once and the unit now runs normally, short-term monitoring may be reasonable while you record the pattern.

If no-start or signal-like faults keep repeating, early diagnosis is better because intermittent wiring faults often worsen.

We will tell you when observation is enough versus when the signal path needs immediate checks.

Common Questions