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View Full Version : S13 AC wiring problems, please help


CASilForty
07-08-2010, 09:08 PM
89 KA24E chassis with 95 KA24DE and ECU. My Silvia as shown in my pic <<<<
The AC System has been converted from old skool to r134 with custom compressor line mods and updated r134 compressor, fully evapped and charged professionally. Thing is when the AC is turned on the light doesnt light, and the compressor only initializes for bout 5 seconds and then shuts off. It blows cool air but its not nearly AC crispy as its not properly circulating the freon! I'm told there is another constant feed wire to the AC to up the voltage forcing the compressor power relay to stay open?? is this right? Anyway thats what I'm told is the prob. We dont seem to know which wire it is from the 95 ECU to the AC compressor, Any s13 AC refit gurus out there? Are we on the right track? lol

Update: Nope it turns out the whole 2nd wire scenario is a red herring. I'm now told by a higher authority, this is not a wiring issue it is a pressure issue, see below.........

killbillsnj
07-10-2010, 12:05 AM
if your ac is short cycling as in turning on and off

it usually means its low on freeon make sure you have enough in there

CASilForty
07-10-2010, 03:30 PM
Thks KillBillsNJ,
Have learned a lot more now. I took the car to a local engine conversion expert who works with Nissans and Drift vehicles. He said theres no 2nd voltage wire, lol. Go figure. He pointed me to the A/C pressure relay sensor which I looped back. Once I did that the system began short cycle repeatedly. I'm told the only reason for this is lo pressure. So the next question becomes: Why would the system show adquate pressure when hooked to the AC charger, but not have enuf to keep the compressor running after initialization? System shows it is adequately pressurized,..... <puzzled look>