Climate Control Unit Power and Ground Circuit Troubleshooting

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2017 Honda Odyssey, 2016 Honda Odyssey, 2015 Honda Odyssey, 2014 Honda Odyssey, and 2013 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

Check the No. C26 (7.5 A) fuse in the driver's under-dash fuse/relay box.
Is the fuse OK?

YES -Go to step 2.

NO -Replace the fuse, and recheck. If the fuse blow again, check for a short in the No. C26 (7.5 A) fuse circuit.
Disconnect climate control unit connector A (28P).
Turn the ignition switch to ON (II).
Measure the voltage between climate control unit connector A (28P) terminal No. 1 and body ground.

Fig 1: Measuring Voltage Between Climate Control Unit Connector Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 5.

NO -Repair an open in the wire between the No. C26 (7.5 A) fuse in the driver's under-dash fuse/relay box and the climate control unit.
Turn the ignition switch to LOCK (0).
Check for continuity between body ground and climate control unit connector A (28P) terminal No. 12 and body ground.

Fig 2: Checking Continuity Between Body Ground And Climate Control Unit Connector Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Check for loose wires or poor connections at climate control unit connector A (28P). If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see CLIMATE CONTROL UNIT REMOVAL/INSTALLATION ).

NO -Check for an open in the wire between the climate control unit and body ground. If the wire is OK, check for poor ground at G403 (see CENTER LOWER CONSOLE SUBHARNESS (AC) ).