Heater Control Power & Ground Circuit Troubleshooting

Is the fuse OK? 

1. YES  - Go to step 2.
2. NO  - Replace the fuse, and recheck.

Fig 1: Measuring The Voltage Between The No. 13 Terminal Of The Heater Control Panel 30P Connector & Body Ground

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage? 

1. YES  - Go to step 5.
2. NO  - Repair open in the wire between the No. 3 fuse in the driver's under-dash fuse/relay box and the heater control panel.

Fig 2: Checking For Continuity Between The No. 29 Terminal Of The Heater Control Panel 30P Connector & Body Ground

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity? 

1. YES  - Check for loose wires or poor connections at the heater control panel 30P connector. If the connections are good, substitute a known-good heater control panel, and recheck. If the symptom/indication goes away, replace the original heater control panel.
2. NO  - Check for an open in the wire between the heater control panel and body ground. If the wire is OK, check for poor ground at G401.