Digital Climate Control (DCC) system

Digital Climate Control (DCC) system

Electrical Climate Control (HVAC) Verified Modification Required

Compatibility Overview

Source Vehicle

Prelude

Generation: 4th generation (BB), JDM digital-climate-control-equipped

Target Vehicle

Prelude

Generation: 4th generation (BB), Australian-market manual-climate car

Installation Difficulty

Easy Basic tools
Moderate Some experience
Difficult Skilled work
Expert Professional

Reference

EV specs → LEB-H5 specs → B18A1 specs → EA specs → EC specs → ED specs → EF specs → EL specs → EM specs → EN specs → ER specs → ES specs → EW specs →
The DCC controller will not operate on its own. A working install requires the full sensor suite (sunlight, cabin, heater-core, evaporator and outside-air sensors), the air-mix motor, power transistor and blower high relay. Fitting the system means recovering the A/C refrigerant (and, on 1992-1993 R12 cars, converting to R134a), draining the coolant, and removing the dash, evaporator and heater unit. New firewall heater hoses are recommended (Honda 79721550000 short and 79725550010 long). The conversion can be staged: control head and manual fan/vent function first, then the A/C and heater-box work.
The complete manual harness must be clipped and re-soldered to the JDM DCC connector, with the power transistor replacing the resistor block and a blower high-speed relay added. The original evaporator thermostat is swapped for the DCC evaporator temperature sensor, and a pass-through must be cut in the heater unit for the heater-core sensor. On right-hand-drive cars the air-mix motor has no factory mounting holes and drives the blend door backwards in the original spot, so it must be re-clocked (retaining nut off, arm repositioned), its full-hot direction bench-verified on 12 volts, and a custom bracket fabricated to hold it. The optional JDM electric water valve and solenoid replace the cable-operated valve and need their own mounting.

Important Caveats

  • • The bare control head is non-functional without the complete sensor set, air-mix motor, power transistor and blower relay.
  • • RHD installations require the air-mix motor to be re-clocked and custom-mounted, with its direction verified before final fitment.
  • • A/C recovery, and R12-to-R134a conversion on 1992-1993 cars, are prerequisites before the system can be used.
  • • The conversion was originally documented on left-hand-drive cars by JRCormier; the RHD-specific deviations come from the follow-up build.

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Community Verification

1
user verified this swap
By Street_Lude via PreludePower
Added 3 days ago

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Sources & References

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