View Full Version : 92 to 90-91 ECU wiring question-AC wire

06-23-2010, 02:14 AM
Sorry to double post but I'm getting no input from the All Trac/GT4 forum.

I have a leak in the system so it loses charge in a couple of days but in the past, when charged, the AC worked fine.

I swapped over to a JDM ECU a couple of years ago and the ECU works fine. I got the diagrams on how to repin from 92-93 to the 90-91 pattern from Gary and everything worked out fine. The only thing that didn't show on the diagrams was what to do with the ATS(AC) wire, #7 on the second plug on the 92 harness. I wasn't too worried about it at the time and hadn't messed with the AC but now that I'm in Texas, I want to get the AC working. On the 90-91 diagram, there is no mention of this wire. It's light blue with a yellow stripe. On the 90-91 diagram, there is nothing showing at #7.

This same wire shows up on the 5S equipted cars as well in 92-93, the only difference is it comes off of pin 15 on the 5S ecu. I'm guessing that ATS means automatic temperature sensor but I'm not sure since it also shows up on the diagram for the non-automatic AC for 92-93. Maybe its means air temperature sensor. In both cases it is terminal #2 on the AC Amplifer.

Anybody that has done this swap have working AC? Where should this wire go in the 90-91 ECU or should the AC work without it?

Any input is greatly appreciated.