History Codes/Intermittent Faults- HVAC System - Dual Zone

If the code set is a history code there is a good chance that the problem is intermittent or no longer exists. If the fault is intermittent, the following diagnostic tests will not be effective in locating the fault. In most cases, the fault must be present to location the problem. Most intermittent problems are caused by faulty electrical connections or wiring. When an intermittent fault is encountered, check for:
^ Poor mating connect halves or terminals not fully seated in the connector body (backed out).
^ Improperly formed or damaged terminal. All connector terminals in a problem circuit should be carefully reformed to increase contact tension.
^ Poor terminal to wire connection. This requires removing the terminal from the connector body to inspect.