2006 Accord EXL I4 : Put in aftermarker radio. Had to use the harness 70-7864-DZ to convert dual zone to single. After wiring it up per instructions, when I turned on switch fan came on and had no controls. Immediately turned off. Removed the harness and plugged the DZ plugs back into head unit. Radio works fine but all HVAC is dead. Can anybody give me some pointers?

 

There are two connectors shown for the Audio-HVAC Display Panel Inputs and Outputs in the Honda Shop Manual. All the HVAC appears to flow through the 22 pin connector (upper LH position as you look at unit). Are you sure you joined this connection?

In any case, suggest getting a shop manual. Check ebay seller automanualsource for a $21.99 downloaded Honda shop manual. The HVAC system manual has diagnostic procedures and how to download DTC's for the system.

good luck