Automatic Temperature Control

The automatic temperature control was never available in Daytonas, only in the Lebarons. I wanted this option ever since I saw it in the factory service manuals, and finally have it installed.

The system is fully automatic, and operates the A/C compressor, fan, and air direction controls to constantly keep the interior as close as possible to the desired temperature. Get into the car on a hot day, and you will be greeted with a blast of recirculated A/C air until it's cooled down, followed by a calm relaxing panel flow of cooled outside air. Get in when it's cold, and the heat comes on as much as possible before again slowing down to a maintenance air flow.

The donor car for this was an 89 LeBaron coupe. The car had obviously been well looked after, it was low miles and immaculate prior to the ugly crash it was in. I needed to get the dash control panel, the Power/Vacuum module, the blend air door actuator, the temperature sensors, and the wiring and connectors for it. Total extract time was about 2 hours.

This diagram shows how all the pieces fit into the dash:

And here are close-up diagrams of the individual pieces:

Once these pieces are installed, it's pretty much a matter of plugging all the wires in, and connecting the extra ones into the car:

White: switched ignition power.
Yellow/Orange: headlight on signal.
Orange: dash illumination.
Black and Black/Green: Ground.
Red: prior to 88, there is also a constant power requirement.

All of these can be tapped into the Navigator connector, which is already really close.

The next problem is that the 87 A/C control is different from the output from the 89 ATC module. I needed to add a small relay. The purple/orange wire from the ATC goes to one side of the coil, and 12v power goes to the other. One of the output contacts goes to ground, the other goes to the car's purple/orange A/C control. This way, when the ATC module sends a low-level ground signal to the relay, the relay allows a higher current ground signal to the car's A/C control.

The only other hassle is at the fan. The connector from the Power module has a Black and Black/Tan wire. The Black one needs to be grounded, and the Black/Tan one connects to the Black/Tan wire already going to the fan. That's it!